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1.
Nuclease activities of the predominantly bacterial population obtained from buffalo rumen were investigated. Optimum temperature
for hydrolysis of both DNA and RNA was 50°C whereas DNAase activity was observed to be stable up to 50°C, a decrease in RNAase
activity was observed even after 40°C. Two pH optima, one at 5.5 and the other at 7.5, were recorded for hydrolysis of DNA.
RNAase activity was maximum between pH 6.0 to 7.0. Whereas DNAase activity was stable near its optimum pH, RNAase activity
was stable between pH 7.0 to 8.5. Mn2+ ions stimulated DNAase activity. It was strongly inhibited by Hg2+, Zn2+, Pb2+ and Ag+. RNAase activity was stimulated by Mg2+ ions and was strongly inhibited by Hg2+, Cu2+, Zn2+ and Ag+. Cysteine hydrochloride and 2-mercaptoethanol stimulated DNAase activity. The activity was strongly inhibited by N-ethylmaleimide,
4-chloromercuribenzoate, 8-quinolinol, iodoacetic acid and 1,10-phenanthroline. RNAase activity was stimulated by cysteine
hydrochloride, reduced glutathione and 2-mercaptoethanol and was strongly inhibited by 4-chloromercuribenzoate, 8-quinolinol
and 2,2′-bipyridyl.
Part of PhD Thesis submitted by the first author to Kurukshetra University. 相似文献
2.
Peña-Montes C González A Castro-Ochoa D Farrés A 《Applied microbiology and biotechnology》2008,78(4):603-612
Aspergillus nidulans PW1 produces an extracellular carboxylesterase activity that acts on several lipid esters when cultured in liquid media containing
olive oil as a carbon source. The enzyme was purified by gel filtration and ion exchange chromatography. It has an apparent
MW and pI of 37 kDa and 4.5, respectively. The enzyme efficiently hydrolyzed all assayed glycerides, but showed preference toward short-
and medium-length chain fatty acid esters. Maximum activity was obtained at pH 8.5 at 40°C. The enzyme retained activity after
incubation at pHs ranging from 8 to11 for 12 h at 37°C and 6 to 8 for 24 h at 37°C. It retained 80% of its activity after
incubation at 30 to 70°C for 30 min and lost 50% of its activity after incubation for 15 min at 80°C. Noticeable activation
of the enzyme is observed when Fe2+ ion is present at a concentration of 1 mM. Inhibition of the enzyme is observed in the presence of Cu2+, Fe3+, Hg2+, and Zn2+ ions. Even though the enzyme showed strong carboxylesterase activity, the deduced N-terminal amino acid sequence of the purified
protein corresponded to the protease encoded by prtA gene. 相似文献
3.
Sarvesh Kumar Soni Jayant Malhar Khire 《World journal of microbiology & biotechnology》2007,23(11):1585-1593
Novel extracellular phytase was produced by Aspergillus niger NCIM 563 under submerged fermentation conditions at 30 °C in medium containing dextrin and glucose as carbon sources along
with sodium nitrate as nitrogen source. Maximum phytase activity (41.47 IU/mL at pH 2.5 and 10.71 IU/mL at pH 4.0) was obtained
when dextrin was used as carbon source along with glucose and sodium nitrate as nitrogen source. Nearly 13 times increase
in phytase activity was observed when phosphate in the form of KH2PO4 (0.004 g/100 mL) was added in the fermentation medium. Physic-chemical properties of partially purified enzyme indicate the
possibility of two distinct forms of phytases, Phy I and Phy II. Optimum pH and temperature for Phy I was 2.5 and 60 °C while
Phy II was 4.0 and 60 °C, respectively. Phy I was stable in the pH range 1.5–3.5 while Phy II was stable in the wider pH range,
2.0–7.0. Molecular weight of Phy I and Phy II on Sephacryl S-200 was approximately 304 kDa and 183 kDa, respectively. Phy
I activity was moderately stimulated in the presence of 1 mM Mg2+, Mn2+, Ca2+ and Fe3+ ions and inhibited by Zn2+ and Cd2+ ions while Phy II activity was moderately stimulated by Fe3+ ions and was inhibited by Hg2+, Mn2+ and Zn2+ ions at 1 mM concentration in reaction mixture. The Km for Phy I and II was 3.18 and 0.514 mM while Vmax was 331.16 and 59.47 μmols/min/mg protein, respectively. 相似文献
4.
A thermoalkaliphilic lipase of <Emphasis Type="Italic">Geobacillus</Emphasis> sp. T1 总被引:3,自引:0,他引:3
Leow TC Rahman RN Basri M Salleh AB 《Extremophiles : life under extreme conditions》2007,11(3):527-535
A thermoalkaliphilic T1 lipase gene of Geobacillus sp. strain T1 was overexpressed in pGEX vector in the prokaryotic system. Removal of the signal peptide improved protein
solubility and promoted the binding of GST moiety to the glutathione-Sepharose column. High-yield purification of T1 lipase
was achieved through two-step affinity chromatography with a final specific activity and yield of 958.2 U/mg and 51.5%, respectively.
The molecular mass of T1 lipase was determined to be approximately 43 kDa by gel filtration chromatography. T1 lipase had
an optimum temperature and pH of 70°C and pH 9, respectively. It was stable up to 65°C with a half-life of 5 h 15 min at pH
9. It was stable in the presence of 1 mM metal ions Na+, Ca2+, Mn2+, K+ and Mg2+ , but inhibited by Cu2+, Fe3+ and Zn2+. Tween 80 significantly enhanced T1 lipase activity. T1 lipase was active towards medium to long chain triacylglycerols (C10–C14)
and various natural oils with a marked preference for trilaurin (C12) (triacylglycerol) and sunflower oil (natural oil). Serine
and aspartate residues were involved in catalysis, as its activity was strongly inhibited by 5 mM PMSF and 1 mM Pepstatin.
The T
m for T1 lipase was around 72.2°C, as revealed by denatured protein analysis of CD spectra. 相似文献
5.
Hideaki Yamada Akihiko Nagao Hiroshi Nishise Yoshiki Tani 《Bioscience, biotechnology, and biochemistry》2013,77(9):2333-2339
NAD+-dependent glycerol dehydrogenase from Cellulomonas sp. NT3060 was purified by a procedure of 10 steps involving crystallization. Dihydroxyacetone was identified as the oxidation product of glycerol with the enzyme. The purified enzyme did not lose activity on heating below 60°C. The enzyme oxidized other alcohols such as 1,2-propanediol, 2,3-butanediol and glycerol-α-monochlorohydrin, beside glycerol. The enzyme activity was inhibited by p-chloromercuribenzoate, Zn2+, Cu2+ and Cd2+. Oxidation of glyberol was activated by Na+ and reduction of dihydroxyacetone was activated by K+ at pH 7.5. 相似文献
6.
Ashraf F. Elbaz Ahmed Sobhi Ahmed ElMekawy 《Bioprocess and biosystems engineering》2015,38(4):767-776
The discovery of novel bacterial cyclodextrin glucanotransferase (CGTase) enzyme could provide advantages in terms of its production and relative activity. In this study, eight bacterial strains isolated from soils of a biodiversity-rich vegetation in Egypt based on their hydrolyzing activity of starch, were screened for CGTase activity, where the most active strain was identified as Bacillus lehensis. Optimization process revealed that the using of rice starch (25 %) and a mixture of peptone/yeast extract (1 %) at pH 10.5 and 37 °C for 24 h improved the bacterial growth and enzyme activity. The bacterial CGTase was successively purified by acetone precipitation, gel filtration chromatography in a Sephadex G-100 column and ion exchange chromatography in a DEAE-cellulose column. The specific activity of the CGTase was increased approximately 274-fold, from 0.21 U/mg protein in crude broth to 57.7 U/mg protein after applying the DEAE-cellulose column chromatography. SDS-PAGE showed that the purified CGTase was homogeneous with a molecular weight of 74.1 kDa. Characterization of the enzyme exhibited optimum pH and temperature of 7 and 60 °C, respectively. CGTase relative activity was strongly inhibited by Mg2+, Zn2+, Al3+ and K+, while it was slightly enhanced by 5 and 9 % with Cu2+ and Fe2+ metal ions, respectively. 相似文献
7.
Ya-Wei Shi Li-Xi Niu Xia Feng Jing-Ming Yuan 《World journal of microbiology & biotechnology》2006,22(7):675-680
Summary A d-hydantoinase was expressed in the soluble form by a recombinant E. coli strain, pE-HDT/E. coli BL21 in LB medium. The enzymatic activity of cultured cells reached 5.2–6.5 IU/ml culture at a cell turbidity of 10 at 600 nm.
The expressed enzyme was efficiently purified by three steps, ammonium sulfate fractionation, Phenyl-Sepharose hydrophobic
interaction chromatography and Sephacryl S-200 size-exclusion chromatography. With the above purification process, the enzyme
was purified to more than 95% purity as estimated by SDS-PAGE. The overall recovery of enzymatic activity was 54.4% and the
specific activity for substrate dl-hydantoin achieved 48 U/mg. The purified enzyme appeared as a dimer with a molecular mass of 103 kDa, as measured by size-exclusion
chromatography. The enzyme was stable from pH 6 to 12 with an optimum pH at 9.5 The optimum temperature of the enzyme was
45 °C and it activity was rapidly lost over 55 °C. Divalent metal ions, including Co2+, Mn2+ and Ni 2+ ions obviously enhanced the enzymatic activity, while Zn2+ ion had a slight inhibitory effect. In addition, the dissociation of purified enzyme into its subunits occurred in the presence
of 1 mM Zn2+ ion. The effect of different metal ions on the d-hydantoinase activation/attenuation was discussed. 相似文献
8.
The objective was to determine the effects of boar seminal plasma and hen's egg yolk on chemotaxis and phagocytosis of porcine and bovine polymorphonuclear neutrophils (PMNs) in vitro. Chemotactic activity of PMNs was determined following culture for 90 min in a blind well chamber. Phagocytosis was assayed after co-culture of PMNs with sperm for 60 min. In the presence of ≥ 5% boar seminal plasma, chemotactic activity of PMNs was reduced (P < 0.05) in both pigs (from 1126.1 to 934.2-1009.1 cells/mm2) and in cows (from 1067.1 to 768.9-800.0 cells/mm2). Furthermore, ≥ 5% boar seminal plasma reduced (P < 0.05) leukocyte phagocytosis in pigs (26.2-32.1%) and cows (27.2-30.0%) compared to controls (41.7 and 42.1%, respectively). Although 20% hen's egg yolk increased (P < 0.05) chemotactic activity of PMNs in pigs (from 790.4 to 1006.1 cells/mm2) and cows (from 789.9 to 953.5 cells/mm2), egg yolk increased (P < 0.05) phagocytotic activity of porcine PMNs (from 24.3 to 33.8%), but not the activity of bovine PMNs (15.1 vs 15.8% in controls). Boar seminal plasma and caffeine reduced (P < 0.05) the egg yolk-induced increase in chemotaxis in both species (from 988.6 to 795.2 or 813.2 cells/mm2 in pigs and from 953.5 to 779.4 or 833.8 cells/mm2 in cows), and phagocytotic activities of PMN (from 33.8% to 15.2 or 13.3%) only in pigs (but not in cows; 11.2-15.1%). In conclusion, hen's egg yolk increased chemotactic activity of PMNs in both pigs and cows, whereas egg yolk increased only phagocytosis of PMNs in pigs, but not in cows. Even in the presence of egg yolk, boar seminal plasma and caffeine significantly reduced chemotactic activity of PMNs in pigs and cows, and phagocytotic activity of porcine PMNs. 相似文献
9.
Mohsen Mohamed Selim Asker Mohamed Fawzy Ramadan Samir Khalf Abd El-Aal Ebtsam Mokhtar Mohamed El-Kady 《World journal of microbiology & biotechnology》2009,25(5):789-794
Trehalose synthase (TSII) from Corynebacterium nitrilophilus NRC was successively purified by ammonium sulphate precipitation, ion exchange chromatography on DEAE-cellulose and gel filtration
chromatography on Sephadex G-100 columns. The specific activity of the trehalose synthase was increased ~200-fold, from 0.14
U mg−1 protein to 28.3 U mg−1 protein. TSII was found to be a monomeric protein with a molecular weight of 67–69 kDa. Characterization of the enzyme exhibited
optimum pH and temperature were 7.5 and 35°C, respectively. The purified enzyme was stable from pH 6.6 to 7.8 and able to
prolong its thermal stability up to 35°C. The enzyme activity was inhibited strongly by Zn2+, Hg2+ and Cu2+ and moderately by Ba2+, Fe2+, Pb2+ and Ni2+. Other metal ions Ca2+, Mg2+, Co2+, Mn2+ and EDTA had almost no effect. 相似文献
10.
Francois Niyongabo Niyonzima 《Preparative biochemistry & biotechnology》2013,43(7):738-759
A fungal alkaline protease of Scopulariopsis spp. was purified to homogeneity with a recovery of 32.2% and 138.1 U/mg specific activity on lectin-agarose column. The apparent molecular mass was 15 ± 1 kD by sodium dodecyl sulfate polyacryalamide gel electrophoresis (SDS-PAGE). It was a homogenous monomeric glycoprotein as shown by a single band and confirmed by native PAGE and gelatin zymography. The enzyme was active and stable over pH range 8.0–12.0 with optimum activity at pH 9.0. The maximum activity was recorded at 50°C and remained unaltered at 50°C for 24 hr. The enzyme was stimulated by Co2+ and Mn2+ at 10 mM but was unaffected by Ba2+, Mg2+, Cu2+, Na+, K+, and Fe2+. Ca2+ and Fe3+ moderately reduced the activity (~18%); however, a reduction of about 40% was seen for Zn2+ and Hg2+. The enzyme activity was completely inhibited by 5 mM phenylmethylsulfonyl fluoride (PMSF) and partially by N-bromosuccinimide (NBS) and tocylchloride methylketone (TLCK). The serine, tryptophan, and histidine may therefore be at or near the active site of the enzyme. The protease was more active against gelatin compared to casein, fibrinogen, egg albumin, and bovine serum albumin (BSA). With casein as substrate, Km and Vmax were 4.3 mg/mL and 15.9 U/mL, respectively. An activation was observed with sodium dodecyl sulfate (SDS), Tween-80, and Triton X-100 at 2% (v/v); however, H2O2 and NaClO did not affect the protease activity. Storage stability was better for all the temperatures tested (?20, 4, and 28 ± 2°C) with a retention of more than 85% of initial activity after 40 days. The protease retained more than 50% activity after 24 hr of incubation at 28, 60, and 90°C in the presence (0.7%, w/v) of commercial enzymatic and nonenzymatic detergents. The Super Wheel–enzyme solution was able to completely remove blood staining, differing from the detergent solution alone. The stability at alkaline pH and high temperatures, broad substrate specificity, stability in the presence of surfactants and oxidizing and bleaching agents, and excellent compatibility with detergents clearly suggested the use of the enzyme in detergent formulations. 相似文献
11.
Microbulbifer strain CMC-5 was isolated from decomposing seaweeds, and was found to degrade agar, alginate, carboxymethyl cellulose, carrageenan,
xylan, and chitin. The extracellular agarase enzyme from strain CMC-5 was purified 103-fold by ultrafiltration, ion-exchange
chromatography, using diethylaminoethyl sepharose FF, and gel filtration, using sephacryl S-300HR, with a yield of 6.7%. Zymogram
and protein staining of the purified agarase on a SDS-polyacrylamide gel revealed a single band, with an apparent molecular
weight of 59 kDa. The purified enzyme was endo-type β-agarase, as it was able to hydrolyze the β-1, 4 glycosidic linkages
of agarose, releasing neoagarotetraose and neoagarohexaose as the end products. The optimum pH and temperature of agarase
were 7 and 50°C, respectively. Thermal stability studies indicated that the agarase retained 62% of its activity after incubating
at 50°C for 30 min. Treatment with EDTA reduced the agarase activity by 54%. The agarase activity was stimulated by the presence
of Ca2+ and Mg2+ ions; whereas, Zn2+, Hg2+, Cu2+, Fe2+, and Co2+ abolished the activity. Further, the presence of NaCl at concentrations lower than 100 mM caused a decrease in the agarase
activity; whereas, the activity was enhanced up to a concentration of 500 mM. 相似文献
12.
Dattatray Bedade Jan Deska Sandip Bankar Samir Bejar Rekha Singhal Salem Shamekh 《Preparative biochemistry & biotechnology》2013,43(6):549-555
AbstractTruffles are symbiotic hypogeous edible fungi (form of mushroom) that form filamentous mycelia in their initial phase of the growth cycle as well as a symbiotic association with host plant roots. In the present study, Tuber maculatum mycelia were isolated and tested for extracellular amylase production at different pH on solid agar medium. Furthermore, the mycelium was subjected to submerged fermentation for amylase production under different culture conditions such as variable carbon sources and their concentrations, initial medium pH, and incubation time. The optimized conditions after the experiments included soluble starch (0.5% w/v), initial medium pH of 7.0, and incubation time of 7 days, at room temperature (22?±?2?°C) under static conditions which resulted in 1.41?U/mL of amylase. The amylase thus obtained was further characterized for its biocatalytic properties and found to have an optimum activity at pH 5.0 and a temperature of 50?°C. The enzyme showed good thermostability at 50?°C by retaining 98% of the maximal activity after 100?min of incubation. The amylase activity was marginally enhanced in presence of Cu2+ and Na+ and slightly reduced by K+, Ca2+, Fe2+, Mg2+, Co2+, Zn2+, and Mn2+ ions at 1?mM concentration. 相似文献
13.
Om Prakash Mahe Talat S. H. Hasan Rajesh K. Pandey 《Biotechnology and Bioprocess Engineering》2008,13(2):210-216
Enzyme urease is extracted from the discarded seeds of pumpkin. Urease was purified to apparent homogeneity (5.2 fold) by
heat treatment at 48 ± 1°C and gel filtration through Sephadex G-200. Effect of model metal ions on the activity of the homogeneous
enzyme preparation (sp. activity 353 U/mg protein, A280/A260 = 1.12) of soluble as well as immobilized enzyme was investigated. The soluble and immobilized urease has been used for the
quantitative estimation of general water pollution with heavy metal ions like Hg2+, Cu2+, Cd2+, and Co2+. The measurements of the urease residual activity have been carried out in tris-acetate buffer after pre-incubation of model
metal salt. The inhibition was found to be biphasic with an initial rapid loss of activity and remainder in slow phase of
10∼15 min. The immobilization was done in 3.5% alginate beads leading to 86% of entrapment. There was no leaching of the enzyme
over a period of 15 days at 4°C. The beads were fairly stable up to 50°C and exhibited activity even at −10°C. The inhibition
by these ions was non-competitive and irreversible, hence could not be restored by dialysis. Based on the values of inhibition
constant Ki the heavy-metal ions were found to inhibit urease in the following order Hg2+ > Cu2+ > Cd2+ > Co2+. 相似文献
14.
15.
Dalel Daâssi Héla Zouari-Mechichi Alicia Prieto María Jesús Martínez Moncef Nasri Tahar Mechichi 《World journal of microbiology & biotechnology》2013,29(11):2145-2155
A white-rot basidiomycete, isolated from decayed acacia wood (from Northwest of Tunisia) and identified as Trametes sp, was selected in a broad plate screening because of its ability to decolorize and dephenolize olive oil mill wastewater (OMW) efficiently. The major laccase was purified and characterized as a monomeric protein with apparent molecular mass of 61 kDa (SDS-PAGE). It exhibits high enzyme activity over broad pH and temperature ranges with optimum activity at pH 4.0 and a temperature of 60 °C. The purified laccase is stable at alkaline pH values. The enzyme retained 50 % of its activity after 90 min of incubation at 55 °C. Using ABTS, this laccase presented K m and V max values of 0.05 mM and 212.73 μmoL min?1 mg?1, respectively. It has shown a degrading activity towards a variety of phenolic compounds. The purified laccase was partially inhibited by Fe2+, Zn2+, Cd2+ and Mn2+, while Cu2+ acted as inducer. EDTA (10 mM) and NaN3 (10 mM) were found to completely inhibit its activity. 73 % OMW was dephenolized after 315 min incubation at 30 °C with 2 U mL?1 of laccase and 2 mM HBT. 相似文献
16.
Vinod Chhokar Seema Vikas Beniwal Raj Kumar Salar K. S. Nehra Anil Kumar J. S. Rana 《Biotechnology and Bioprocess Engineering》2010,15(5):793-799
A tannase (E.C. 3.1.1.20) producing fungal strain was isolated from soil and identified as Aspergillus heteromorphus MTCC 8818. Maximum tannase production was achieved on Czapek Dox minimal medium containing 1% tannic acid at a pH of 4.5
and 30°C after 48 h incubation. The crude enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography.
Diethylaminoethyl-cellulose column chromatography led to an overall purification of 39.74-fold with a yield of 19.29%. Optimum
temperature and pH for tannase activity were 50°C and 5.5 respectively. Metal ions such as Ca2+, Fe2+, Cu1+, and Cu2+ increased tannase activity, whereas Hg2+, Na1+, K1+, Zn2+, Ag1+, Mg2+, and Cd2+ acted as enzyme inhibitors. Various organic solvents such as isopropanol, isoamyl alcohol, benzene, methanol, ethanol, toluene,
and glycerol also inhibited enzyme activity. Among the surfactants and chelators studied, Tween 20, Tween 80, Triton X-100,
EDTA, and 1, 10-o-phenanthrolein inhibited tannase activity, whereas sodium lauryl sulfate enhanced tannase activity at 1%
(w/v). 相似文献
17.
Hadiseh Dadras Sergey Boryshpolets Amin Golpour Tomas Policar Miroslav Blecha Borys Dzyuba 《Journal of fish biology》2019,95(4):1137-1144
Several factors regulating activation of spermatozoon motility in Eurasian burbot, Lota lota, including osmolality, calcium (Ca2+) ions, and temperature were investigated. Spermatozoon motility in Eurasian burbot, Lota lota was assessed at 4 and 30°C in seminal fluid, isotonic media (with and without Ca2+) and hypotonic media (with and without Ca2+). Spermatozoa were spontaneously activated in seminal fluid at 20°C and the maximum motility was recorded at 30°C, which is out of the spawning temperature range, indicating that no risk of activation occurs during routine semen handling in artificial insemination. Initiation of spermatozoon motility in L. lota is mediated by Ca2+ and sensitivity to Ca2+ is dependent on temperature. 相似文献
18.
The endo-β-1, 4-xylanase gene xynA from Aspergillus sulphureus, encoded a lack-of-signal peptide protein of 184 amino acids, was de novo synthesized by splicing overlap extension polymerase
chain reaction according to Pichia pastoris protein’s codon bias. The synthetic DNA, composed of 572 nucleotides, was ligated into the downstream sequence of an α-mating
factor in a constitutive expression vector pGAPzαA and electrotransformed into the P. pastoris X-33 strain. The transformed yeast screened by Zeocin was able to constitutively secrete the xylanase in yeast–peptone–dextrose
liquid medium. The heterogenous DNA was stabilized in the strain by 20-times passage culture. The recombinant enzyme was expressed
with a yield of 120 units/mL under the flask culture at 28°C for 3 days. The enzyme showed optimal activity at 50°C and pH 2.4–3.4.
Residual activity of the raw recombinant xylanase was not less than 70% when fermentation broth was directly heated at 80°C
for 30 min. However, the dialyzed xylanase supernatant completely lost the catalytic activity after being heated at 60°C for
30 min. The recombinant xylanase showed no obvious activity alteration by being pretreated with Na2HPO4-citric acid buffer of pH 2.4 for 2 h. The xylanase also showed resistance to certain metal ions (Na+, Mg2+, Ca2+, K+, Ba2+, Zn2+, Fe2+, and Mn2+) and EDTA. These biochemical characteristics suggest that the recombinant xylanase has a prospective application in feed
industry as an additive. 相似文献
19.
Phytase from Nocardia sp. MB 36 was purified (9.65-fold) to homogeneity by acetone precipitation, ion exchange, and molecular sieve chromatography. Native polyacrylamide gel electrophoresis (PAGE) and zymogram analysis showed a single active protein in the purified enzyme preparation. Sodium dodecyl sulfate (SDS)-PAGE analysis showed that phytase was a monomeric protein with a molecular weight of approximately 43 kDa. Phytase exhibited activity and stability over a broad pH range (2–8) and elevated temperatures (50–80°C), and utilized several phosphate compounds as substrates. Phytase was extremely resistant to pepsin and trypsin. Various metal ions viz. Fe2+, Co2+, and Mn2+, and NH4+, ethylenediaminetetraacetic acid or EDTA and phenylmethylsulfonyl fluoride or PMSF had no influence on activity, while Ca2+ and Zn2+ enhanced activity by 15 % and 3.58 %, respectively. SDS caused significant reduction in enzyme activity (41.8 %), while 2,3-butanedione did so moderately (15.9 %). Features of Nocardia sp. MB 36 phytase suggest a potential for animal feed applications. 相似文献
20.
《Bioscience, biotechnology, and biochemistry》2013,77(10):2139-2144
Turkey pancreatic phospholipase (TPP) has been purified from delipidated pancreases. The purification included ammonium sulfate fractionation, acidic (pH 5) treatment, followed by sequencial column chromatographies on DEAE-cellulose, Sephadex G-75, and reverse phase high pressure liquid chromatography. The purified enzyme was found to be a monomeric protein with molecular mass of 14 kDa. The optimal activity was measured at pH 8 and 37°C using egg yolk emulsion as substrate. Our results show that the enzyme (TPP) was not stable for 1 h at 60°C, and that bile salt and Ca2+ were required for the expression of the purified enzyme. The sequence of the N-terminal amino acids of the purified enzyme shows a very close similarity between TPP and all other known pancreatic phospholipases. 相似文献