共查询到20条相似文献,搜索用时 15 毫秒
1.
Bin Wu Licheng Wu Daijie Chen Zhijun Yang Minyu Luo 《Journal of industrial microbiology & biotechnology》2009,36(3):451-459
A novel fibrinolytic enzyme from Fusarium sp. CPCC 480097, named Fu-P, was purified to electrophoretic homogeneity using ammonium sulfate precipitation and ion exchange
and gel filtration chromatography. Fu-P, a single protein had a molecular weight of 28 kDa, which was determined by SDS-PAGE
and gel filtration chromatography. The isoelectric point of Fu-P determined by isoelectric focusing electrophoresis (IEF)
was 8.1, and the optimum temperature and pH value were 45°C and 8.5, respectively. Fu-P cleaved the α-chain of fibrin (ogen)
with high efficiency, and the β-chain and γ-γ (γ-)-chain with lower efficiency. Fu-P activity was inhibited by EDTA and PMSF,
and the enzyme exhibited a high specificity for the chymotrypsin substrate S-2586. Fu-P was therefore identified as a chymotrypsin-like
serine metalloprotease. The first 15 amino acids of the N-terminal sequence of Fu-P were Q-A-S–S-G-T-P-A-T-I-R-V-L-V–V and
showed no homology with that of other known fibrinolytic enzymes. This protease may have potential applications in thrombolytic
therapy and in thrombosis prevention. 相似文献
2.
Mika Murata Masaru Nagai Makoto Takao Akira Suzuki Takuo Sakai Takao Terashita 《Mycoscience》2001,42(5):479-482
Trehalase from the culture filtrate ofLentinula edodes was purified and characterized. Molecular masses were estimated to be 158 kDa and 79–91 kDa by gel filtration and SDS-PAGE
under the reduced condition, respectively. The enzyme was composed of two identical subunits and contained carbohydrate molecules.
The optimum temperature and pH were obtained at around 40°C and pH 5.0, respectively. The enzyme was stable up to 40°C and
in a range pH of 4–10 at 30°C. It cleaved α-1,1 linkages of trehalose, but not α-1,4, α-1,6 or β-1,4 glycosyl linkages, and
was defined as an acid trehalase. 相似文献
3.
A. -A. Amirul S. L. Khoo M. N. Nazalan M. S. Razip M. N. Azizan 《Folia microbiologica》1996,41(2):165-174
A. niger produced α-glucosidase, α-amylase and two forms of glucoamylase when grown in a liquid medium containing raw tapioca starch
as the carbon source. The glucoamylases, which formed the dominant components of amylolytic activity manifested by the organism,
were purified to homogeneity by ammonium sulfate precipitation, ion-exchange and two cycles of gel filtration chromatography.
The purified enzymes, designated GA1 and GA2, a raw starch digesting glucoamylase, were found to have molar masses of 74 and
96 kDa and isoelectric points of 3.8 and 3.95, respectively. The enzymes were found to have pH optimum of 4.2 and 4.5 for
GA1 and GA2, respectively, and were both stable in a pH range of 3.5–9.0. Both enzymes were thermophilic in nature with temperature
optimum of 60 and 65°C, respectively, and were stable for 1 h at temperatures of up to 60°C. The kinetic parametersK
m andV showed that with both enzymes the branched substrates, starch and amylopectin, were more efficiently hydrolyzed compared
to amylose. GA2, the more active of the two glucoamylases produced, was approximately six to thirteen times more active towards
raw starches compared to GA1. 相似文献
4.
Canakci S Belduz AO Saha BC Yasar A Ayaz FA Yayli N 《Applied microbiology and biotechnology》2007,75(4):813-820
The gene encoding an α-l-arabinofuranosidase from Geobacillus caldoxylolyticus TK4, AbfATK4, was isolated, cloned, and sequenced. The deduced protein had a molecular mass of about 58 kDa, and analysis
of its amino acid sequence revealed significant homology and conservation of different catalytic residues with α-l-arabinofuranosidases belonging to family 51 of the glycoside hydrolases. A histidine tag was introduced at the N-terminal
end of AbfATK4, and the recombinant protein was expressed in Escherichia coli BL21, under control of isopropyl-β-D-thiogalactopyranoside-inducible T7 promoter. The enzyme was purified by nickel affinity
chromatography. The molecular mass of the native protein, as determined by gel filtration, was about 236 kDa, suggesting a
homotetrameric structure. AbfATK4 was active at a broad pH range (pH 5.0–10.0) and at a broad temperature range (40–85°C),
and it had an optimum pH of 6.0 and an optimum temperature of 75–80°C. The enzyme was more thermostable than previously described
arabinofuranosidases and did not lose any activity after 48 h incubation at 70°C. The protein exhibited a high level of activity
with p-nitrophenyl-α-l-arabinofuranoside, with apparent K
m and V
max values of 0.17 mM and 588.2 U/mg, respectively. AbfATK4 also exhibited a low level of activity with p-nitrophenyl-β-d-xylopyranoside, with apparent K
m and V
max values of 1.57 mM and 151.5 U/mg, respectively. AbfATK4 released l-arabinose only from arabinan and arabinooligosaccharides. No endoarabinanase activity was detected. These findings suggest
that AbfATK4 is an exo-acting enzyme. 相似文献
5.
Yuichi Uno Sae Hashidume Osamu Kurita Takayuki Fujiwara Keiichi Nomura 《Acta Physiologiae Plantarum》2010,32(4):713-718
α-Mannosidase (EC 3.2.1.24) was purified from ‘Iseimo’, a native variety of Dioscorea opposita Thunb. Before purification, we investigated the composition of a viscous polysaccharide that interferes with column chromatography
procedures. The polysaccharide consisted mainly of mannose, and also contained uronic acid. We used the cationic detergent
cetylpyridinium chloride (CPC) to remove the polysaccharide. CPC treatment decreased viscosity without affecting α-mannosidase
activity. We purified α-mannosidase 2,650-fold. The optimal pH of the enzyme was 6.0 and the optimum temperature was 65°C.
The K
m value for p-nitrophenyl-α-d-mannopyranoside was 0.35 ± 0.03 mM. Activity was inhibited by swainsonine but not kifunensine. The enzyme cleaved α-1,2 linkages
preferentially to α-1,6 and α-1,3 linkages. The M
r of purified α-mannosidase was estimated to be 250–260 kDa by gel filtration and native-PAGE. Four polypeptides (86, 83, 80,
and 28 kDa) were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. It is unclear whether the polypeptides
are encoded by one gene or multiple genes. However, N-terminal sequence analysis suggested that post-translational cleavage
and/or glycosylation resulted in the three large fragments, if these amino acids were encoded by the same gene. Homology searches
and characterization of the enzyme’s properties indicated that Iseimo α-mannosidase belongs to the glycoside hydrolase family
38 proteins, and to the Class II mannosidase group. 相似文献
6.
Nack-Shick Choi Jae Jun Song Dong-Min Chung Young Jae Kim Pil Jae Maeng Seung-Ho Kim 《Journal of industrial microbiology & biotechnology》2009,36(3):417-426
A novel fibrinolytic enzyme (AJ) was purified from Staphylococcus sp. strain AJ screened from Korean salt-fermented Anchovy-jeot. Relative molecular weight of AJ was determined as 26 kDa by using SDS-PAGE and fibrin zymography. Based on a 2D gel, AJ
was found to consist of three active isoforms (pI 5.5–6.0) with the same N-terminal amino acid sequence. AJ exhibited optimum pH and temperature at 2.5–3.0 and 85°C, respectively.
AJ kept 85% of the initial activity after heating at 100°C for 20 min on the zymogram gel. The Michaelis constant (K
m) and K
cat values of AJ towards α-casein were 0.38 mM and 19.73 s−1, respectively. AJ cleaved the Aα-chain of fibrinogen but did not affect the Bβ- and γ-chains, indicating that it is an α-fibrinogenase.
The fibrinolytic activity was inhibited by diisopropyl fluorophosphate, indicating AJ is a serine protease. Interestingly,
AJ was very stable at acidic condition, SDS, and heat (100°C), whereas it was easily degraded at neutral and alkaline conditions.
In particular, AJ formed an active homo-dimer in the pH range from 7.0 to 8.0. To our knowledge, a similar combination of
acid and heat stability has not yet been reported for other fibrinolytic enzymes. 相似文献
7.
Zhiqiang Wu Guoliang Jiang 《International journal of peptide research and therapeutics》2008,14(2):75-80
Using N-α-benzoyl-l-arginine p-nitroanilide (BApNA) as substrate, trypsin-like enzymes (TLEs) were purified from mysis (Neomysis japonica) following two chromatographic steps, Sephacryl S100 HR gel filtration and Benzamidine-Sepharose 4B affinity. They presented
a high stability in the raw material, retaining over 45% of the initial activity after 30 days of storage at pH 8.0, 45 °C.
The purified TLEs had relative molecular mass between 32 kDa and 33 kDa. With higher stability and greater activity, they
had similar stability and activity profiles (pH 6.0–11.0, 15–65 °C) as bovine trypsin but had a different optimum temperature
(35 °C for trypsin and 45 °C for TLEs). Similar to bovine trypsin, the purified TLEs could be activated by Ca2+ and Mg2+. And the purified TLEs also showed similar inhibitory profiles as bovine trypsin with the exception of chicken egg ovomucoid
(CEOM), an effective inhibitor of bovine trypsin but less so for purified TLEs. Having TLEs with physiological efficiency
3.6 times that of bovine trypsin, the use of mysis as a source for commercial production of TLEs is discussed. 相似文献
8.
The production of auxins, such as indole-3-acetic acid (IAA), by rhizobacteria has been associated with plant growth promotion,
especially root initiation and elongation. Six indole-producing bacteria isolated from the rhizosphere of legumes grown in
Saskatchewan soils and identified as Pantoea agglomerans spp. were examined for their ability to promote the growth of canola, lentil and pea under gnotobiotic conditions and for tryptophan
(Trp)-dependent IAA production. Five of the isolates enhanced root length, root weight or shoot weight by 15–37% in at least
one of the plant species, but isolates 3–117 and 5–51 were most consistent in enhancing plant growth across the three species.
Indole concentrations in the rhizosphere of plants grown under gnotobiotic conditions increased in the presence of the rhizosphere
isolates and when Trp was added 3 days prior to plant harvest. Isolates 3–117, 5–51 and 5–105 were most effective in increasing
rhizosphere indole concentrations. Colony hybridization confirmed that all of the isolates possessed the ipdC gene which codes for a key enzyme in the Trp-dependent IAA synthetic pathway. The activity of amino acid aminotransferase
(AAT), catalyzing the first step in the Trp-dependent synthetic pathway, was examined in the presence of Trp and other aromatic
amino acids. All of the isolates accumulated Trp internally and released different amounts of IAA. The production of IAA from
the isolates was greatest in the presence of Trp, ranging from 2.78 to 16.34 μg mg protein−1 in the presence of 250 μg of Trp ml−1. The specific activity of AAT was correlated with the concentration of IAA produced in the presence of Trp but not when tyrosine
(Tyr), phenylalanine (Phe) or aspartate (Asp) was used as a sole nitrogen source. Isolate 3–117, which produced significant
concentrations of IAA in the presence and absence of Trp, was able to use aromatic amino acids as sole sources of nitrogen
and was most consistent in enhancing the growth of canola, lentil and pea may have potential for development as a plant growth-promoting
inoculant.
Responsible Editor: Peter A. H. Bakker. 相似文献
9.
A novel PHB depolymerase from a thermophilic Streptomyces sp. MG was purified to homogeneity by hydrophobic interaction chromatography and gel filtration. The molecular mass of the
purified enzyme was 43 kDa as determined by size exclusion chromatography and 41 kDa by SDS-PAGE. The optimum pH and temperature
were 8.5 and 60 °C respectively. The enzyme was stable at 50 °C and from pH 6.5–8.5. The enzyme hydrolyzed not only bacterial
polyesters, i.e. poly(3-hydroxybutyric acid and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), but also synthetic, aliphatic
polyesters such as polypropiolactone, poly(ethylene adipate) and poly(ethylene succinate).
Revisions requested 9 November 2005; Revisions received 12 December 2005 相似文献
10.
Uchida H Hojyo M Fujii Y Maeda Y Kajimura R Yamanaka H Sakurai A Sakakibara M Aisaka K 《Applied microbiology and biotechnology》2007,74(4):805-812
Formate oxidase was found in cell-free extracts of Debaryomyces vanrijiae MH201, a soil isolate. After purification by column chromatography, the preparation showed a protein band corresponding to
a molecular mass (MM) of 64 kDa on sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The MM, estimated by a gel filtration,
was 99 kDa. The preparation showed two and three bands on isoelectric focusing under denaturing and native conditions, respectively.
These results suggest that the preparation contained three isoforms, each of which might be composed of αα, αβ, and ββ subunits
with apparently similar MM. The preparation acted on formate with K
m and V
max values of 11.7 mM and 262 μmol min−1 mg−1, respectively, at pH 4.5 and 25°C, but showed no evidence of activity on the other compounds tested. The optimum pH and temperature
were pH 4.0 and 35°C, respectively. The preparation showed activities of 85% of the initial activity after storage at pH 6.0
and 4°C for 8 weeks. When 10 mM formaldehyde was reacted with 2.0 U ml−1 of the enzyme preparation at pH 5.5 and room temperature in the presence of 2.0 U ml−1 of a microbial aldehyde oxidase and 100 U ml−1 of catalase for 180 min, neither of formate nor formaldehyde was detected, suggesting that the reaction involved the quantitative
conversion of formaldehyde to carbon dioxide. 相似文献
11.
Kohji Ishihara Rieko Iwai Momoko Yoshida Mika Morishita Hitomi Yamaguchi Nobuyoshi Nakajima 《World journal of microbiology & biotechnology》2011,27(1):17-24
A novel keto ester reductase (Chlorella sorokiniana keto ester reductase, CSKER) from Chlorella sorokiniana SAG 211-8k cells was purified. The CSKER had a monomeric structure based on gel filtration chromatography (37 kDa) and SDS–polyacrylamide
gel electrophoresis (34 kDa). The purified CSKER showed a high reducing activity with β-keto esters, in particular, ethyl 4-chloro-3-oxobutanoate and ethyl 2-chloro-3-oxobutanoate. However, the purified enzyme
did not show any reducing activity with α-keto esters and 2-chlorobenzoylformamide (aromatic α-keto amide). The CSKER catalyzed
the reduction of ethyl 4-chloro-3-oxobutanoate, ethyl 3-oxobutanoate, and methyl 3-oxobutanoate to the corresponding (R)-, (S)-, and (S)-hydroxy ester, respectively, with high enantioselectivity (>99% e.e.), respectively. Furthermore, the reduction of ethyl
2-methyl-3-oxobutanoate by CSKER exclusively yielded the corresponding syn-(2R, 3S)-hydroxy ester. The purified CSKER was inactive with NADH, used instead of NADPH. None of the keto ester-reducing enzymes
already isolated from other microorganisms was identical to the CSKER. These results suggested that CSKER is a novel keto
ester reductase that has not yet been reported. 相似文献
12.
Cho HY Seo MJ Park JU Kang BW Kim GY Joo WH Lee YC Cho YS Jeong YK 《Journal of microbiology (Seoul, Korea)》2011,49(6):1018-1021
A fibrinolytic enzyme was found in a Gram-negative bacterium, Aeromonas sp. JH1. SDS-PAGE and fibrinzymography showed that it was a 36 kDa, monomeric protein. Of note, the enzyme was highly specific
for fibrinogen molecules and the hydrolysis rate of fibrinogen subunits was highest for α, β, and γ chains in that order.
The first 15 amino acids of N-terminal sequence were X-D-A-T-G-P-G-G-N-V-X-T-G-K-Y, which was distinguishable from other fibrinolytic
enzymes. The optimum pH and temperature of the enzyme were approximately 8.0 and 40°C, respectively. Therefore, these results
provide a fibrinolytic enzyme with potent thrombolytic activity from the Aeromonas genus. 相似文献
13.
A new phycoerythrin, SCH-phycoerythrin, was purified from Synechococcus sp. ECS-18 by DEAE-Sephacel anion exchange chromatography and Sephacryl S-300 gel filtration. The protein pigment had an
absorbance maximum at 542 nm and a fluorescence maximum at 565 nm. The native molecular mass was approximately 219 kDa as
determined by gel filtration, and sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated the presence of two
subunits, with molecular mass of 19 and 17.9 kDa. These observations are consistent with the (αβ)6 subunit composition that is characteristic of phycoerythrins. The α- and β-subunits showed immunological identity by Ouchterlony
double immunodiffusion with an anti-phycoerythrin antiserum. The DNA sequence of the SCH-phycoerythrin gene was determined
by PCR amplification using primers based on the conserved N-terminal amino acid sequence of the α- and β-subunits of phycoerythrins. 相似文献
14.
Paecilomyces variotii IRI017 was isolated as a formaldehyde-resistant fungus from wastewater containing formaldehyde. The fungus grew in a medium
containing 0.5% formaldehyde and had consumed formaldehyde completely after 5 days. Alcohol oxidase was purified from the
fungus grown on methanol. A 20-fold purification was achieved with a yield of 44%. The molecular mass of the purified enzyme
was estimated to be 73 and 450 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration chromatography,
respectively, suggesting that the enzyme consists of six identical subunits. The N-terminal amino acid sequence of the subunit
was TIPDEVDIII. The enzyme showed an absorption spectrum typical of a flavoprotein and had a noncovalently bound flavin different
from FAD, FMN, and riboflavin. The pH optimum of the enzyme activity was pH 6–10. The enzyme was stable in the pH range of
pH 5–10. The enzyme retained full activity after incubation at 50°C for 30 min. The enzyme oxidized not only methanol but
also lower primary alcohols and formaldehyde. The K
m values for methanol, ethanol, and formaldehyde were 1.9, 3.8, and 4.9 mmol l−1, respectively. 相似文献
15.
The photorespiratory enzyme L-serine:glyoxylate amino- transferase (SGAT; EC 2.6.1.45) was purified from Arabidopsis thaliana leaves. The f'mal enzyme was approximately 80 % pure as revealed by sodium dodecyl sulfatepolyacrylamide gel electrophoresis with silver staining. The identity of the enzyme was confirmed by LC/MS/MS analysis. The molecular mass estimated by gel filtration chromato- graphy on Sephadex G-150 under non-denaturing conditions, mass spectrometry (matrix-assisted laser desorption/ ionization/time of flight technique) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 82.4 kDa, 42.0 kDa, and 39.8 kDa, respectively, indicating dimer as the active form. The optimum pH value was 9.2. The enzyme activity was inhibited by aminooxyacetate and β-chloro-L-alanine both compounds reacting with the carbonyl group of pyridoxal phosphate. The enzyme's transaminating activity with L-alanine and glyoxylate as substrates was approximately 55 % of that observed with L-serine and glyoxylate. The lower Kmvalue (1.25 mM) for L-alanine, compared with that of other plant SGATs, and the kcat/Km(Ala) ratio being approxi- mately 2-fold higher than kcat/Km(Ser) suggested that, during photorespiration, Ala and Ser are used by Arabidopsis SGAT with equal efficiency as amino group donors for glyoxylate. The equilibrium constant (Keq), derived from the Haldane relation, for the transamination reaction between L-serine and glyoxylate with the formation of hydroxypyruvate and glycine was 79.1, strongly favoring glycine synthesis. However, it was accompanied by a low Km value of 2.83 mM for glycine. A comparison of some kinetic properties of the studied enzymes with the recombinant Arabidopsis SGATs previously obtained revealed substantial differences. The ratio of the velocity of the transamination reaction with L-alanine and glyoxylate as substrates versus that with L-serine and glyoxylate was 1:1.8 for the native enzyme, whereas it was 1:7 for the recombinant SGAT. Native SGAT showed a much lower Km value for L-alanine compared to the recombinant enzyme. 相似文献
16.
Koma D Yamanaka H Moriyoshi K Ohmoto T Sakai K 《Extremophiles : life under extreme conditions》2007,11(6):769-779
A novel extracellular serine protease derived from Thermoanaerobacter tengcongensis, designated tengconlysin, was successfully overexpressed in Escherichia coli as a soluble protein by recombination of an N-terminal Pel B leader sequence instead of the original presequence and C-terminal
6× histidine tags. The purified protein was activated by 0.1% sodium dodecyl sulfate (SDS) treatment but not by thermal treatment.
The molecular weight of tengconlysin estimated by SDS-polyacrylamide gel electrophoresis analysis and gel filtration chromatography
was 37.9 and 36.2 kDa, respectively, suggesting that the enzyme is monomeric. The N-terminal sequence of mature tengconlysin
was LDTAT, suggesting that it is a preproprotein containing a 29 amino acid presequence (predicted from the SigP program)
and a 117 amino acid prosequence in the N-terminus. The C-terminal putative propeptide (position 469–540 in the preproprotein)
did not inhibit the protease activity. The optimum temperature for tengconlysin activity was 90°C in the presence of 1 mM
calcium ions and the optimum pH ranged from 6.5 to 7.0. Activity inhibition studies suggest that the protease is a serine
protease. The protease was stable in 0.1% SDS and 1–4 M urea at 70°C in the presence of calcium ions and was activated by
the denaturing agents. 相似文献
17.
Isolation of a gene from Leuconostoc citreum B/110-1-2 encoding a novel dextransucrase enzyme 总被引:1,自引:0,他引:1
Fraga Vidal R Moulis C Escalier P Remaud-Siméon M Monsan P 《Current microbiology》2011,62(4):1260-1266
The amplicon encoding dextransucrase DSR-F from Leuconostoc citreum B/110-1-2, a novel sucrose glucosyltransferase (GTF)-specific for α-1,6 and α-1,3 glucosidic bond synthesis, with α-1,4 branching
was cloned, sequenced, and expressed into Escherichia coli JM109. Recombinant enzyme catalyzed oligosaccharides synthesis from sucrose as donor and maltose acceptor. The dsrF gene encodes for a protein (DSR-F) of 1,528 amino acids, with a theoretical molecular mass of 170447.72 Da (~170 kDa). From
amino acid sequence comparison, it appears that DSR-F possesses the same domains as those described for GTFs. However, the
variable region is longer than in other GTFs (by 100 amino acids) and two APY repeats (a 79 residue long motif with a high
number of conserved glycine and aromatic residues, characterized by the presence of the three consecutive residues Ala, Pro,
and Tyr) were identified in the glucan binding domain. The DSR-F catalytic domain possesses the catalytic triad involved in
the glucosyl enzyme formation. The amino acid sequence of this domain shares a 56% identity with catalytic domain of the alternansucrase
ASR from L. citreum NRRL B-1355 and with the catalytic domain of a putative alternansucrase sequence found in the genome of L. citreum KM20. A truncated active variant DSR-F-∆SP-∆GBD of 1,251 amino acids, with a molecular mass of 145 544 Da (~145 kDa), was
obtained. 相似文献
18.
Xiaodan Liu Kun Meng Yaru Wang Pengjun Shi Tiezheng Yuan Peilong Yang Huiying Luo Yingguo Bai Bin Yao 《World journal of microbiology & biotechnology》2009,25(9):1633-1642
A gene, aga-MJ11, encoding an α-galactosidase (EC 3.2.1.22) was cloned from Pedobacter nyackensis MJ11 CGMCC 2503, expressed in Escherichia coli, and biochemically characterized. The gene consisted of 2,163 nucleotides encoding a 720 amino acid–protein with a theoretical
molecular weight of 82.6 kDa. The deduced amino acid sequence of Aga-MJ11 shared the highest identity of 51% to an α-galactosidase
from Parabacteroides distasonis (YP_001301506), which belongs to glycoside hydrolase (GH) family 36. Purified recombinant Aga-MJ11-H showed optimal activity
at pH 5.5 and 40°C, was stable at pH 4.0–10.0, retained ~80% of the maximum activity at 30°C (the optimum temperature for
freshwater fish), exhibited tolerance to some proteases, and had a wide substrate specificity (pNPG, melidiose, stachyose
and raffinose). All these features make Aga-MJ11 potentially useful for applications in aquaculture. The enzyme studied in
the present work may represent a novel GH-36 α-galactosidase from the genus Pedobacter.
X. Liu and K. Meng contributed equally to this work. 相似文献
19.
Wang SL Lin YT Liang TW Chio SH Ming LJ Wu PC 《Journal of industrial microbiology & biotechnology》2009,36(1):65-73
A lipase-producing bacterium was isolated and identified as Pseudomonas monteilii TKU009. A lipase (F2) and lipase-like materials (F1) were purified from the culture supernatant of P. monteilii TKU009 with soybean powder as the sole carbon/nitrogen source. The molecular mass of F1 and F2 was estimated to be 44 kDa
by SDS-PAGE and gel filtration. The optimum pH, optimum temperature, and pH and thermal stabilities of F2 were 7, 40°C, 8–11,
and 50°C; and of F1 were 6, 40°C, 6–7, and 50°C, respectively. F2 was completely inhibited by EDTA and slightly by Mg2+, Fe2+, Mn2+, and SDS. F1 was completely inhibited by EDTA and Fe2+ and strongly by Zn2+, Mn2+, Ca2+, Mg2+, and SDS. The activities of both the enzymes were enhanced by the addition of non-ionic surfactants Triton X–100 and Tween
40, especially for F1. F2 preferably acted on substrates with a long chain (C10–C18) of fatty acids, while F1 showed a broad
spectrum on those with chain length of C4–C18. The marked activity of F2 in organic solvents makes it an ideal choice for
application in a water-restricted medium including organic synthesis.
Li-June Ming is a visiting Professor at the National Cheng Kung University. 相似文献