1.
Production And Optimization Of Thermostable Recombinant A- Amylase Ffrom Geobacillus Sbs-4S
by Sabah mansoor | Dr. Muhammad Tayyab | Dr. Tanveer | Ms.Faiza masood.
Material type: ; Format:
print
Publisher: 20130Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1845,T] (1).
2.
Isolation ,Identification And Characterization Of Phytase Producing Bacteria
by Hafsa Raiaz | Dr Muhammad Tayyab | Miss Asma Waris | Miss Saeeda | IBBT.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2012Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1865,T] (1).
3.
Optimization For The Production Of Amylase By Geobacillus Sbs-4S
by Nasreen abdul jabbar | Dr. Muhammad Tayyab | Dr. Ali Raza awan | Ms. Asma waris.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1905,T] (1).
4.
Effect Of Medicinal Plant Extracts On Genes Expression In Human Cervical Carcinoma
by Atika saeed | Dr. Muhammad Tayyab | DR | Ms. Huma mujahid.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 1999,T] (1).
5.
Refolding And Characterization Of Thermostable Recombinant Amylase From Geobacillus Sbs-4S
by Amna jawad | Dr. Muhammad Tayyab | Dr. Sehrish | Ms. Shagufta saeed.
Material type: ; Format:
print
; Literary form:
not fiction
Publisher: 2014Dissertation note: Abstract Availability: Items available for loan: UVAS Library [Call number: 2027,T] (1).
6.
DNA Based Characterization of Xylanase Gene From Hyperthermophilic Archeon
by Saima Zulfiqar (2012-VA-539) | Dr. Muhammad Tayyab | Dr. Faiza Masood | Dr.Sehrish Firyal.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Blank CD Availability: Items available for loan: UVAS Library [Call number: 2233-T] (1).
7.
Effect Of Date Palm Pollen On The Plasma And Intra-Testicular Testosterone Levels Of Male Albino Rats
by Yasir Arfat | Dr. Muhammad Tayyab | Dr. Abu Saeed Hashmi | Dr. Ali Raza.
Material type: ; Format:
print
Publisher: 2012Dissertation note: Considerable evidence exists for the efficacy and safety of short courses of low
dose testosterone therapy for treating infertility and delayed puberty. This treatment is
associated with high levels of patient satisfaction. There is not yet sufficient evidence for
the routine use of other therapies. Experimentally, date extract had been shown to
increase sperm count and increase stimulating concentration of testosterone count in
guinea pigs and to enhance spermatogenesis, follicle stimulating hormone (FSH) and
luteinizing hormone (LH) in rats. Intratesticular testosterone (ITT) is thought to play a
key role in the control of spermatogenesis but is rarely measured.
The present study is therefore designed to examine the effect of date palm pollen
(DPP) (Phoenix dactylifera) on the plasma and intra-testicular testosterone levels using
male albino rat as an experimental animal with the hope that the result of this study may
pave the way for treating male infertility and delayed puberty.
Adult male albino rats were divided into two groups (control and experimental).
Experimental group were given date palm pollen (DPP) suspension in a single oral dose
of 120 mg/kg of body weight for 35 days. Where as the control were given equal amount
of distilled water. Blood samples of control and experimental groups were taken for
measurement of serum testosterone levels at day 0, 12, 24 and finally at day 36.Aanimals
were sacrificed. Testes were removed for gross and biological studies. Intra-testicular
testosterone levels were measured at the end of experimental studies.
There were no statistically significant differences in the variable of control group.
Experimental group who received DPP suspension for 35 days showed statistically significant increase in body weight, weight of paired testes, serum and intra- testicular testosterone levels as compared to control group.
Availability: Items available for loan: UVAS Library [Call number: 1411,T] (1).
8.
Bioconversion Of Wheatbran To Glucose By Gluoamylase From Aspergillus Fumigatus
by Hassan Ali | Dr. Muhammad Tayyab | Dr. Abu Saeed Hashmi | Dr. Asif Nadeem.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2012Dissertation note: Background:
Glucose is produced by hydrolysis of starch. Many crops like maize, rice and wheat can be used as the source of starch. Wheat bran is an agricultural waste byproduct which can be converted to glucose using glucoamylase. Wheat bran is very cheap source for carbohydrates. It is mainly composed of carbohydrates; hemicelluloses, cellulose and starch. Glucoamylase is an enzyme that yields glucose from the nonreducing chain of amylose and amylopectin by hydrolyzing ? -1,3, ?-1, 4 and ?-1,6 linkages of starch. Glucoamylases are produced by plants, animals and microorganism. Microbes, including bacteria, yeast and fungi are major source for the production of glucoamylases. Aspergillus fumigatus is found in soil and in decaying organic matter and it has an essential role in carbon and nitrogen recycling.
Hypothesis: A. fumgiatus might be a good source for the production of glucoamylase through submerged fermentation conditions.
Parameters/Methodlogy: Aspergillus fumigatus was identified macro and microscopically. Enzyme production was measured by DNS method. The effects of different sources of carbon, phosphorous and nitrogen on glucoamylase production were also examined. In order to get the optimum production of glucoamylase, the effect of temperature, pH and incubation period was analysed separately.
Methodology: Initially the A. fumigatus was isolated and conditions were optimized for the growth and production of glucoamylase. Production of enzyme was examined by DNS method. The effects of various carbon, nitrogen and phosphorous sources were examined on the production of glucoamylase. From the present study it was concluded that maximum production of glucoamylase can be obtained from A. fumigatus using wheat bran as the substrate at pH of 4.8, temperature of 40oC with an incubation time of three days.The use of wheat bran as substrate wheat bran for the production of glucoamylase will reduce the cost for the production of glucoamylase.
Availability: Items available for loan: UVAS Library [Call number: 1509,T] (1).
9.
Biochemical Identification Of Various Causes Of Anemia In Females From District Pakpattan
by Hafiz. Muhammad Toqeer | Dr. Muhammad Tayyab | Dr. Abu Saeed Hashmi | Mr. Muhammad.
Material type: ; Format:
print
Publisher: 2013Dissertation note: Anemia is estimated to be affecting almost 600 millions people all over the globe and is regarded as deficiency in Hemoglobin concentration. The decreased amount of hemoglobin in blood could not been able to fulfill the oxygen demand of tissues in body. Keeping in view the above situation, a study was planned to investigate the various types of anemia in dist. Pakpattan.
One hundred blood samples were collected from females randomly selected from various parts of district Pakpattan. The samples were divided into two groups on the basis of age. Group A contains the patients with age between 14 to 26 years where as Group B consist of patients with age 27 to 40 years. Samples were processed in-order to estimate Complete Blood Count, serum iron level, serum ferritin levels, vitamin B12 assay and HPLC based estimation of various variants of hemoglobin.
The results demonstrated that 62% of the total female population of dist. Pakpattan was found to be anemic. Among Group A, 66.66% were anemic due to iron deficiency and 33.33% were due to chronic disease. Group B contained 59.09% anemic, out of these patients, 57.69% were anemic due to iron deficiency, 38.46% due to chronic disease and 2.27% due to deficiency of Vitamin B12. Iron deficiency was found to be the major cause of anemia that is followed by anemia due to chronic disease and Vitamin B12 deficiency. The intensity of anemia was 5% higher in young age females (Group A) as compared to the elder age females (Group B).
This work provided the information about the prevalence of various types of anemia in the population of dist. Pakpattan. The data will be helpful for developing strategy for the control of anemia in future. Further study with a large number of samples, is required throughout the country for the establishment of a data base that will be a good step to control various types of anemia.
Availability: Items available for loan: UVAS Library [Call number: 1611,T] (1).
10.
Biochemical & Molecular Characterization Of Locally Isolated Extremophile
by Iram Murtaza | Dr. Muhammad Tayyab | Ms. Sehrish | Ms. Shagufta Saeed.
Material type: ; Format:
print
Publisher: 2013Dissertation note: Extremophiles are microorganisms with the ability to survive under extreme of conditions. Due to their extreme stability, these microorganisms produce unique biocatalysts that have been exploited in various industrial processes. These micro-organisms are unique factories for the production of enzymes that have great potential for agriculture, textile, pharmaceutical, poultry and detergent industries.
The present study was conducted for the isolation and characterization of alkaliphile. The sampling was done from spring located in Rawat, Pakistan. Optimization of growth conditions was done by growing the microorganism at various conditions including temperature, pH and salt concentration. The microorganism was identified on the basis of biochemical characteristics as well as on the basis of 16S rRNA gene sequence. Regarding the molecular characterization, the genomic DNA was isolated from the strain and was utilized for the amplification of 16S rRNA gene. The PCR product was ligated in pTZ57R/T. The ligation mixture was utilized for the transformation of E.coli DH5-? cells. The presence of insert in recombinant pTZ57R/T was confirmed by single and double restriction with EcoR1 and Hind III which resulted in the liberation of DNA fragment. The gene sequence was utilized for the phylogenetic analysis. The microorganism was found to be Gram positive rods involved in the production of catalase, amylase, protease, enzymes and gave positive results for Mannitol, Voges Proskauer Tests while negative for citrate utilization and nitrate reduction test. 16S rRNA gene sequence analysis demonstrated that the newly isolated strain showed maximum homology with various members of genus Exiguobacterium. The newly isolated strain was declared a new member of genus Exiguobacterium and was named as Exiguobacterium UVAS-01.
Availability: Items available for loan: UVAS Library [Call number: 1706,T] (1).
11.
Molecular Identification Of Bacterial Infections In Human Spontaneous Abortions
by Zarish Noreen | Dr. Muhammad Tayyab | Mr. Akhar Ali | Ms. Faiza Masood.
Material type: ; Format:
print
; Literary form:
drama
Publisher: 2013Dissertation note: A miscarriage medically known as spontaneous abortion is defined as a pregnancy that ends by itself spontaneously before the fetus has reached a viable gestational age of 20 to 24 weeks. Brucellosis, Q fever and Chlamydiosis are the zoonotic diseases that are widely distributed around the world and are caused by gram negative Brucella melitensis, Brucella abortus, Coxiella burnetii, Chlamydophila pecorum and Chlamydophila abortus. The current study was carried out for the molecular detection of five zoonotic bacteria in spontaneous human abortion cases. The complete blood analysis is helpful for the early diagnosis of infections in pregnancy. In this study complete blood count (CBC) and liver function test (LFT) of all patients was carried out and it was found that hemoglobin, total leukocyte count (TLC), serum bilirubin, serum alkaline phosphate, serum aspartate aminotransferase (AST), serum alanine aminotransferase (ALT) values were found to be increased as compared to normal values which indicated the fact that these parameters may fluctuate in human abortion cases.
Similarly in the present study DNA was isolated from blood samples by adopting the procedure of Genex kit. Five sets of primers were used as described earlier for identification of bacteria (Berri et al. 2009; Bally et al. 1992). In our local population of pregnant women the risk of different bacteria was evaluated and multiplex polymerase chain reaction (m-PCR) results were analyzed to determine the presence of different bacterial pathogens in all patients. The percentage prevalence of each bacterial pathogen was calculated. The prevalence of B. abortus was found to be maximum (11.6%) while B. melitensis was not detected in any patient. However, C. burnetii and C. pecorum was found to be 3.33% each and C. abortus was found to be 6.66% respectively. In healthy females no infection was observed. Quantitative data in this study was statistically analyzed using Statistical Package for Social Sciences (SPSS version 17.0). The m-PCR assay developed in current study provides a new tool for Brucellosis, Chlamydiosis and Q fever diagnosis. The application of this assay may be helpful to control animal and human infections. The study will result in the development of a diagnosis test that can be utilized for the identification of bacterial infections at early stage of pregnancy and will be helpful to reduce the number of abortions by treatment of specific bacterial infections.
Availability: Items available for loan: UVAS Library [Call number: 1712,T] (1).
12.
Production Of Polyhydroxybutyrate By Submerged Fermentation Using Agricultural By-Products
by Zainab Bibi (2015-VA-802) | Dr. Muhammad Tayyab | Dr. Shagufta Saeed | Prof. Dr. Aftab Ahmad Anjum.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: Increasing non-degradable waste on planet is the major environmental concern these days. Hence, there is an absolute need of “eco-friendly” plastics. Polyhydroxybutyrate (PHB) is the most popular biodegradable as well as eco-friendly polymer. However, high production cost of PHB is still a major problem in the commercialization of biodegradable plastics. Process economics revealed that the use of cheap and renewable carbon substrates such as agro-industrial wastes can account for 40-50% reduction in overall production cost.
In present study wheat bran, gram bran, rice bran, wheat straw and sesame oil cake were used to check PHB production using Azotobacter vinelandii NRRL-146641. For this purpose, 0.5ml inoculum was added in fermentation media and kept for incubation at 24-48 hrs. After incubation, both physical and chemical parameters such as (substrate water ratio, incubation time, inoculum volume, pH, agitation rate and nitrogen sources) were optimized. Optimized culture medium was centrifuged and obtained sediment was then used for analysis.
It was found that Azotobacter vinelandii in Rice bran contained medium gives maximum yield of PHB (248mg/100mL) at 8% substrate water ratio after 96 hours of incubation period (292mg/100mL), at 1.5 mL of volume of inoculum (304 mg/100mL), at pH 6.0 (316 mg/100mL), at 160 rpm agitation rate (416mg/100ml) at 0.3 % of yeast extract (446 mg/100mL) and 0.25% (436mg/100mL) of peptone. Obtained data was then analyzed by means of ONE-WAY ANOVA and through LSD test. Availability: Items available for loan: UVAS Library [Call number: 2855-T] (1).
13.
Evaluation Of Bioactive Peptides/ Proteins/ Alkaloids From Extracts Of Croton Tiglium, Lawsonia Inermis And Eruca Sativa Against Mastitis Causing Bacterial Strains
by Rubia Saeed (2011-VA-377) | Dr. Muhammad Tayyab | Dr. Abu Saeed Hashmi | Dr. Muhammad Nawaz.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: Mastitis is considered as one of the most prevalent disease in dairy animals of Pakistan. Bacteria which are found in most mastitis cases are S. aureus, S. agalactiae and E. coli. Infections caused by these bacteria are being treated by various antibiotics but due to their development of resistance towards these drugs, there is need to explore some alternatives like medicinal plant extracts for the treatment of mastitis. Croton tiglium, Eruca sativa and Lawsonia inermis have been reported to have antimicrobial activity, thus the extracts of these medicinal plants will be explored to their antimicrobial activity against mastitis causing bacterial strains.
Present study purpose was to evaluate the bioactive proteins/alkaloids/peptides from extract of C. tiglium, E. sativa and L. inermis against mastitis causing bacterial strains. For this purpose, the leaves and seeds samples of selected medicinal plants (C. tiglium, E. sativa and L. inermis) were collected from Bagh-e-Jinnah and were identified from Department of Botany, University of the Punjab, Lahore. The ethanolic and aqueous extracts were prepared to evaluate the antimicrobial activity against mastitis causing bacterial strains. For this purpose, dust free leaves and seeds of selected plants were cut into small pieces, homogenized in ethanol/buffer and centrifuged. The resulting supernatant was then collected to check its antimicrobial activity against S. agalactiae, S. aureus and E.coli. Antimicrobial activity was analyzed by well diffusion method. Regarding the antimicrobial activity assay, the overnight grown cultures of the selected microbial strains was spread on the LB agar plates and the extracts was applied to wells incubated was done at 37°C for overnight. Inhibition zone was measured. Then the extracts having maximum activity were purified by GC.MS and the nature of extract was examined. All experiments were performed in triplicates so mean and average of the values was taken. Availability: Items available for loan: UVAS Library [Call number: 2853-T] (1).
14.
DNA Based Characterization Of Protease Gene From Geobacillussp.Sbs-4s
by Anam Shabbir (2012-VA-608) | Dr. Muhammad Tayyab | Ms. Huma Mujahid | Prof. Dr. Tahir Yaqub.
Material type: ; Literary form:
not fiction
Publisher: 2014Dissertation note: Proteases are hydrolytic enzymes responsible for the hydrolysis of proteins(Qadar et al.2004).These enzymes contribute major role in textile and leather industry,accounting 60% of the world wide enzyme market(Nascimento et al.2004).These enzymes are also being used in food ,pharmaceutical ,detergent, brewage sweet industry and as digestive additives in human and animal feed (Wilson, 2012).
Proteases are produced by microbes,animal and plants but microbial proteases are preferred due to ease in production and cheaper cost (Ningthoujam et al.2010).Microbes produce a variety of proteases according to their requirement that are specific in their function (Neurath 1999).Microbes might be involved in the production of intra or extracellular proteases.Extracellular proteases help the organism to absorb and utilize hydrolytic products from proteinious substrates in order to get energy by catabolism or to synthesize the biomolecules through anabolism reactions(Ningthoujamet al.2010).
Proteases can be classified in different ways.On the basis of cutting preferences these can be divided in to two groups:endopeptidases and exopeptidases (Barret and Mcdonald 1985).Exopeptidases are involved in hydrolysis of the peptide bond near N or C terminal whereas endopeptidases are responsible for the hydrolysis of peptide bond, with the chain, distant from the peptide ends(Motyan et al .2013).On the basis of catalytic residues in active site the proteases can be divided into six groups including glutamate,serine, therionine cysteine,aspartate and metalloproteases(Li et al.2013).
Microorganisms occupy all possible environments including habitats that provides appropriate conditions for growth(Sharma et al.2009).Thermophiles have ability to grow at highertemperature whereas other microbes fail to survive.There has been increasing interest in thermophilic bacteria because of their thermostable enzyme(Obeidat et al.2012).Hyperthermophiles can survive in extremely hot environment. Hyperthermophiles occupy the most basal positions of the phylogenetic tree of life(Bouzas et al. 2006). About 70 species of hyperthermophilic bacteria and archea has been isolated from different terrestrial, marine and thermal areas in the world.Hyperthermophiles are very divergent in their phylogeny and physiological properties.Proteolytic enzymes from hyperthermophiles are catalytically active at high temperature and they can alsoretain their catalytic activity in the presence of detergent and other denaturing substances (Stetter et al.1993).
Geobacillusis widely distributed thermophiles isolated from geothermal areas (Chalopagorn et al.2014).On the basis of16SrRNA gene sequences, Geobacillus belongs to Bacillus genetic group 5. It is phenotypically and phylogeneticallyconsistent group of thermophilicbacilli (Rahman et al. 2007).Bacillus and Geobacillus species are the dominant workhorses in industrial biotechnology. These bacteria produce a variety of extracellular enzymes, such as amylases, xylanases, proteases, phytases, carbonic anhydrases, catalases, pectinases. Bacillus and Geobacillus species hasability to grow at acidic, alkaline, neutral pH and at elevated temperature has positioned them among the most important industrial enzyme producers(Satyanarayana et al. 2012).
Geobacillus are gram-positive, rod-shaped, aerobic,endospore-forming obligate thermophiles.The growth temperature for various Geobacillus species ranges from 37 to 75 °C and pH range of 6.0 to 8.5.The members of Geobacillusare homologus to each other and share homology 99% among them(Tayyab et al.2011). The genus Geobacillusthermophilicstrains, produce a variety of thermostable hydrolytic extracellular enzymes, such as proteases, amylases, and lipases used in various industrial applications (Wiegand et al. 2013)
GeobacillusSBS-4S was isolated from a hot spring located in Gilgit, Northern areas of Pakistan.Geobacillus SBS-4S strain is Gram positive, rod-shaped bacteria and occurs in chains. That could grow at a wide range of temperature (45 to 75˚C) and pH ranging 5.5 to 9.5.Geobacillus SBS-4S produced several extracellular enzymes including amylase, protease and lipase.The comparison of the strain SBS-4S with the already reported species of genus Geobacillus showed that SBS-4S is resistant to antibiotics such as streptomycine, spectinomycin and rifampicin(Tayyab et al.2011).
Availability: Items available for loan: UVAS Library [Call number: 2242-T] (1).
15.
Production, Purification & Characterization Of Recombinant Thermostable Phytase And Its Biological Evaluation In Broiler Chicks
by Furqan Sabir (2007-VA-524) | Dr. Muhammad Tayyab | Dr. Abu Saeed Hashmi | Dr. Ali Raza Awan.
Material type: ; Literary form:
not fiction
Publisher: 2017Dissertation note: Phytate is the principle storage form of phosphorus in plants particularly in cereal grains and legumes. Mono-gastric animals doesn’t have ability to utilize phytate as phosphorus source. The animals release the undigested phytate from body with manure that cause environmental pollution. Phytases are responsible for the hydrolysis of phytate, resulting in availability of free phosphorus for the animal. The present study deals with the production and characterization of recombinant thermostable phytase and its biological evaluation in the broiler chicks. The PCR resulted in the amplification of 1.8 kb phytase gene using the genomic DNA of Thermotoga naphthophila as template. The purified PCR product was ligated in pTZ57R/T and the ligated material was utilized for the transformation of E.coli DH5α cells. The positive clones were selected on the basis of blue white screening. The restriction digestion of plasmid DNA from positive clones using NdeI and Hind III resulted in the release insert from the vector. The purified phytase gene after restriction digestion was ligated into pET21a already restricted with the same restriction enzymes and the expression was analyzed using E.coli BL21 CodonPlus (DEL) cells. SDS-PAGE demonstrated the intra-cellular production of recombinant phytase. The conditions were optimized for the optimal production of recombinant phytase (PHYTN). The maximal production of PHYTN was recorded when the BL21 CodonPlus cells having recombinant pET21a having phytase gene were induced with 1.4 mM IPTG and 6 hours post induction incubation period. The recombinant protein was purified using various chromatographic techniques and the purified protein was utilized for characterization. PHYTN showed optimal activity at 80 °C and pH 6 in sodium acetate buffer. The enzyme was found metal dependent and presence of Fe3+ or Cu2+ showed enhancing effect on PHYTN activity. Thermostability studies demonstrated that PHYTN retains 90% residual
SUMMARY
71
activity when the protein was incubated at 80 °C for 1h in the presence of 1.5 mM Fe3+. The kinetic studies of PHYTN demonstrated km and Vmax values of 50 mM and 2500 μmole/min respectively when sodium phytate was used as substrate. The characterized PHYTN was used for poultry trials to check the efficacy of the enzyme in poultry birds.
The results depicted that PHYTN put significant effect on the bird weight gain, feed intake and feed efficiency ratio. Presence of 1000 IU/kg of PHYTN resulted in the weight gain in 3rd, 4th and 5th week of trials from 504.766 to 533.535 g, 767.933 to 823.733 g and 999.833 to 1120.277 g respectively when compared with the control. The study demonstrated that this recombinant thermostable phytase is suitable for poultry feed industry and its domestic production will contribute the economic availability of PHYTN for the poultry feed industry. Availability: Items available for loan: UVAS Library [Call number: 2870-T] (1).
16.
DNA Based Characterization Of Arginase Gene From Geobacillus Sp. SBS-4s
by Raabia Bibi (2012-VA-537) | Dr. Muhammad Tayyab | Dr. Abu Saeed Hashmi | Dr. Muhammad Imran.
Material type: ; Literary form:
not fiction
Publisher: 2015Dissertation note: Geobacillus is a group gram-positive, rod-shaped, aerobic, endospore-forming and obligate thermophilic bacteria, isolated from the diverse habitats, hot springs, thermal environments, terrestrial soils, deep sea sediments (Zeigler, 2014), petroleum and soil of desserts (Claus and Berkeley 1986). It grows at a wide range of temperature from 45 to 75°C and pH ranging from 6.2 to 7.8 (Nazina et al. 2001). These bacteria survives at higher temperature where most of other living species fail to survive (Claus and Berkeley 1986). Geobacillus have achieved a significant population with a worldwide distribution, probably in large part due to adaptive features of their spores (Zeigler, 2014). These can be found singly or in short chains and motile by means of peritrichous flagella and is capable of secreting a wide variety of extracellular and intracellular enzymes i.e amylase, lipase, carboxypeptidase, cellulase, xylanase, protease and galactosidase (Fogarth et al. 1974; Obeidat et al. 2012).
Geobacillus sp. SBS-4S was isolated from hot spring located in Gilgit, Northern areas of Pakistan. It was found to be an aerobic, gram-positive and rod-shaped bacteria having ability to hydrolyze a variety of sugars, carboxylic acids and hydrocarbons at elevated temperatures from 45 to 75°C. SBS-4S was found to be involved in the production of various intra and extra cellular enzymes (Tayyab et al. 2011).
Arginase is the enzyme responsible for the degradation of arginine resulting in the production of urea and ornithine (Kaur et al. 2009). It is accomplished by the cleaving of the guanidinium group from arginine which yields urea (Turras et al. 2008). Arginase present in many mammals (Homo sapiens), Bacilli (cyanobacteria), protozoa (Entamoeba histolytica), yeast (Saccharomyces cerevisiae), fungi (Neurospora crassa) and plants (Lathyrus sativus) etc (Kaur et al. 2009). The crystal structure of arginases have been determined by X ray crystallographic studies. This is a manganese dependent enzyme. The enzyme shows its activity through the metal ion. Metal ion is actively responsible for the incorporation of water molecules essential for the activity of the enzyme. A second proposed mechanism, based on electron paramagnetic resonance (EPR) studies postulates direct coordination of the substrate to manganese and disruption of the aqua bridge. Arginases are homo-oligomers, with a typical subunit mass of 32 to 36 kDa (Bewley et al. 1999).
There are two types of arginases, arginase-I and arginase-II, located in the cytoplasm and mitochondria, respectively. The principal ureagenic enzyme activity arginase-I is most abundant in normal mammalian liver and acts in coordination with the other enzymes of the urea cycle to sequester and eliminate excess nitrogen from the body. The second form arginase-II can be found in many organs, with the highest levels found in kidney and prostate where as lower levels in macrophages and lactating mammary glands (Iyer et al. 2002).
Important role of arginase in controlling the cellular levels of arginine and ornithine, which are required for various critical metabolic processes, including protein synthesis and the production of creatine, polyamines, proline and nitric oxide (NO). Type II arginase is found in a variety of different tissues and have a key role in the regulation of urea cycle arginine metabolism by regulating levels of arginine in the cell (Bewley et al. 1999). The enzyme arginase plays key role in the pathogenesis of pulmonary disorders such as asthma through dysregulation of L-arginine metabolism and modulation of nitric oxide (NO) homeostasis and it also play role in the development of chronic airway remodeling through formation of ornithine with downstream production of polyamines and L-proline, which are involved in processes of cellular proliferation and collagen deposition (Benson et al. 2011). Arginase involved in tissue repair processes by the synthesis of L-ornithine, which is the precursor of polyamines and proline that are involved in cell proliferation and collagen synthesis (Maarsingh et al. 2009).
Genetically engineered arginase as fusion protein with prolonged half-life and increased efficacy are used to treat different tumor lines that inhibit cell proliferation and impaired cellular migration in vitro and in vivo (Li et al. 2013). This is a arginine-degrading and ornithine producing enzyme and is used to treat arginine-dependent cancers (Yu et al. 2013). Chemically modified arginase-II has been employed for the treatment of taper liver tumor and L5178Y murine leukemia (Kaur et al. 2009). The enzyme was cloned and expressed in E. coli and subsequently conjugated to polyethylene glycol to increase the circulating half-life and decrease the immunogenicity of the recombinant mycoplasma enzyme. The human hepatocellular carcinoma, melanoma cell lines and tissue samples do not express argininosuccinate synthetase (ASS), making them auxotrophic for arginine and thus reasonable candidates for arginine deprivation (Yang et al. 2010).
Arginase is induced in murine myeloid cells mainly by T-helper 2 cells cytokines and inflammatory agents and participates in a variety of inflammatory diseases by down-regulation of nitric oxide synthesis, induction of fibrosis and tissue regeneration. In humans, arginase I is constitutively expressed in polymorphonuclear neutrophils and is liberated during inflammation. Myeloid cell arginase-mediated L-arginine depletion profoundly suppresses T cell immune responses and this is a fundamental mechanism of inflammation-associated immunosuppression. Pharmacological interference with L-arginine metabolism is a novel promising strategy in the treatment of cancer, autoimmunity or unwanted immune deviation (Munder, 2009).
Arginase has very important role in nitrogen fixation and fruit ripening (Yu et al. 2013). Putrescine (1,4-butanediamine) is the product obtained from arginine with the highest market value and it is used as an intermediate in a large number of industries, including the pharmaceutical industry, agrochemical industry and textile industry (Turras et al. 2008).
Arginine is a semi-essential amino acid and is the precursor for the formation of nitric oxide (NO) by nitric oxide synthases (Getz and Reardon, 2006). One of the major functions of arginine within the body is as an intermediate in the urea cycle. In the cytosol of hepatocytes, arginase-I removes the guanidine group from arginine to produce urea and ornithine. Urea is then transported from the hepatocyte into the bloodstream and ornithine is used to regenerate arginine within the hepatocyte. Arginine deficiency causes several disorder like, hyper cholesterolemia, hypertension, diabetes mellitus, kidney failure, hyper homo-cysteinemia, smoking, and aging (Alvares et al. 2012). Arginine is used to modulate the cellular immune response during infection. The generation of nitric oxide from arginine is responsible for efficient immune response (Das et al. 2010).
Arginine is synthesised in humans and other mammals from citrulline in two steps through the urea cycle enzymes, argininosuccinate synthetase (ASS) and argininosuccinate lyase (ASL). ASS catalyses the conversion of citrulline and aspartic acid to argininosuccinate, which is then converted to arginine and fumaric acid by ASL (Yang et al. 2010).
Ararinase play important role in conversion of arginine to 1,4–butanediamine (a building block for nylon-4,6), through two main transformations: the hydrolysis of arginine to ornithine and urea; and the decarboxylation of ornithine to 1,4–butanediamine and carbon dioxide. Both steps can be catalyzed chemically or enzymatically (Turras et al. 2008).
The present study deals with the characterization of arginase gene.
Availability: Items available for loan: UVAS Library [Call number: 2244-T] (1).
