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1.
Penicillium cyclopium, grown in stationary culture, produces a type I lipase specific for triacylglycerols while, in shaken culture, it produces a type II lipase only active on partial acylglycerols. Lipase II has been purified by ammonium sulfate precipitation and chromatographies on Sephadex G-75 and DEAE-Sephadex. The enzyme exists in several glycosylated forms of 40-43 kDa, which can be converted to a single protein of 37 kDa by enzymatic deglycosylation. Activity of lipase II is maximal at pH 7.0 and 40 degrees C. The enzyme is stable from pH 4.5 to 7.0. Activity is rapidly lost at temperatures above 50 degrees C. The enzyme specifically hydrolyzes monoacylglycerols and diacylglycerols, especially of medium chain fatty acids. The sequence of the 20 first amino acid residues is similar to the N-terminal region of P. camembertii lipase and partially similar to lipases from Humicola lanuginosa and Aspergillus oryzae, but is different from Penicillium cyclopium lipase I. However, it can be observed that residues of valine and serine at positions 2 and 5 in Penicillium cyclopium lipase II are conserved in Penicillium expansum lipase, of which 16 out of the 20 first amino acid residues are similar to Penicillium cyclopium lipase I.  相似文献   

2.
Interest in lipases from microorganisms, animals, and plants has greatly increased in the past decade due to their applications in biotransformations and organic syntheses. We are reporting the purification and characterization of two lipases from the fungus, Ophiostoma piliferum, a saprophytic organism commonly found on wood. A major and a minor lipase have been co-purified by hydrophobic interaction chromatography on octyl sepharose FF, followed by ion exchange chromatography on Q sepharose FF. The lipases bound very tightly to octyl sepharose resulting in greater than 100-fold purification in this one step. The major lipase has a molecular weight of approximately 60 kDa, a pI of 3.79, and is glycosylated as determined by PAS staining. The minor lipase, which composes 10% of the total protein, has a pI of 3.6, and molecular weight of approximately 52 kDa and did not stain with the PAS reagent. Deglycosylation of the major lipase produced two proteins of lower molecular weight, a 55 kDa protein and a 52 kDa protein. The deglycosylated protein at 52 kDa co-migrates with the minor lipase on SDS-PAGE gels. N-terminal amino acid sequencing of the major and minor lipases indicated both lipases have the same N-termini and MALDI-TOF mass spectral analysis showed similar peptide patterns. Available data indicate that the lipases are derived from the same protein and appear to differ in their post-translational modification as evidenced by their pIs and molecular weight difference. The pH rate profile and thermal stability were determined for the purified O. piliferum lipase and were consistent with a mesophilic lipase. In aqueous solution, the lipases exhibited a higher rate of hydrolysis for p-nitrophenylbutyrate (C4) than for p-nitrophenylstearate (C18), which is an unexpected result.  相似文献   

3.
圆弧青霉碱性脂肪酶的分离纯化和特性   总被引:3,自引:0,他引:3  
圆弧青霉突变株PG37 发酵液经离心、硫酸铵盐析、疏水层析、阴离子交换层析和凝胶过滤分离纯化得到了比活性为每毫克蛋白质5 200 u 的碱性脂肪酶, 纯化倍数16 .5 , 得率33.2% , 在聚丙烯酰胺凝胶电泳(PAGE)和SDS聚丙烯酰胺凝胶电泳(SDSPAGE)上均呈现单一蛋白质条带。SDSPAGE 和凝胶过滤分别测得酶的分子量为27.5 kD和29 kD, 表明该酶以单体形式存在。N末端10 个氨基酸的序列测定结果为ATADAAAFPD, 与已知的碱性脂肪酶的N 末端序列没有同源性。酶学特性研究结果表明, 该酶的最适作用温度为25 ℃, 在30 ℃以下稳定,40 ℃处理20 min 仅残留30 % 酶活性;pH 稳定范围在6.5~10.5 , 最适pH 为10 .0 。低浓度的碱性蛋白酶对PG37 碱性脂肪酶活性的影响较小, 可同时添加在洗涤剂中。  相似文献   

4.
[目的]从土壤中筛选到一株新的产右旋糖酐酶的真菌F1001,为酶法制备药用级右旋糖酐提供新的右旋糖酐酶产生菌株.[方法]通过形态特征和ITS rDNA序列分析方法鉴定菌株.利用硫酸铵盐析、Sepharose 6B凝胶柱纯化,得到纯度较高的酶蛋白.以右旋糖酐70 kDa为底物,对右旋糖酐酶酶学性质及催化机理进行研究.[结...  相似文献   

5.
A method of isolation and purification of lipase (EC 3.1.1.3) from the germ of wheat (Triticum aestivum) is described. Electrophoretically homogeneous preparation of the enzyme (specific activity, 622.5 x x 10(-3) mumol/min per mg protein) was obtained after purification in 61 times. The molecular weight of the enzyme, determined by gel chromatography, was 143 +/- 2 kDa. The optimal conditions for the enzyme were 37 degrees and pH 8.0. Homogeneous preparation of the lipase exhibited high thermal stability: over 20% of original activity was retained after incubation of the preparation at high temperatures (60-90 degrees) for 1 h at pH 8.0.  相似文献   

6.
Two types of extracellular lipases (I and II) from Trichosporon fermentans WU-C12 were purified by acetone precipitation and successive chromatographies on Butyl-Toyopearl 650 M, Toyopearl HW-55F and Q-Sepharose FF. The molecular weight of lipase I was 53 kDa by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and 160 kDa by gel filtration, while that of lipase II was 55 kDa by SDS-PAGE and 60 kDa by gel filtration. For the hydrolysis of olive oil, the optimum pH and temperature of both the lipases were 5.5 and 35°C, respectively. The lipases showed stable activities after incubation at 30°C for 24 h in a pH range from 4.0 to 8.0. The thermostability of lipase I for 30 min at a reaction pH of 5.5 was up to 40°C, while that of lipase II under the same conditions was up to 50°C. Both lipases could hydrolyze the 1-, 2-, and 3-positions of triolein, and cleave all three ester bonds, regardless of the position in the triglyceride.  相似文献   

7.
When the protease inhibitor from Penicillium cyclopium was mixed with the acid protease of the mold at acid pH formed a precipitate consisting of a enzyme-inhibitor complex. The precipitation occurred maximally at pH 3.0 and was interfered with by increasing amounts of salts and other protein. Subsequent incubation of the complex brought about inactivation of the enzyme and the inactivation was found to be accompanied by modification of the enzyme so that less was precipitable with trichloroacetic acid. Paper chromatography revealed that the enzyme on complete inactivation had been degraded to several fragments or polypeptides. The inhibitor acted on the enzyme in a catalytic fashion, bringing about degradation of more than a stoichiometric amount of enzyme. The proposed mechanism of the inhibitor action involved acceleration of auto-digestion of the enzyme which splits the molecule into small fragments and abolishes the activity.  相似文献   

8.
9.
A protease inhibitor produced by Penicillium cyclopium on solid cultures of wheat bran was purified by means of column chromatography on Duolite A-2 and DEAE-cellulose, acetone precipitation and lyophilization. The purified inhibitor obtained as a white, floccose and hygroscopic substance was monodisperse by ultracentrifugal analysis. It was found to be an acidic macro-molecule of a molecular weight of about 5000. The chemical analyses rejected the possibility of the presence of amino acids, peptides, sugars, amino sugars, or uronic acids in the inhibitor molecule.

Properties of a protease inhibitor from Penicillium cyclopium were studied. The pH range of the inhibitor action is restricted to acid pH, optimally at pH 3. Increasing temperature accelerates its action upon enzyme. The inhibitor causes enzyme inactivation in proportion to its concentration. It is fairly stable in an acid solution but unstable in an alkaline solution. It undergoes destruction by heat, hydrogen peroxide and ascorbic acid. The inhibitor reversibly combines with Al3+, Fe3+, Ag+ and Cu2+ to produce a precipitate. Salts interfer with the inhibitor activity. Generally, acid proteases from various penicillia are susceptible to the inhibitor while those from other genera are resistant.  相似文献   

10.
The major extracellular protein of Penicillium cyclopium has been isolated from its culture media and purified by ammonium sulfate fractionation, gel, and ion-exchange chromatography. We show this secreted protein to be endopeptidase. The molecular weight is approximately 32,000, the pI is 5.0, and the pH optimum using a variety of protein and synthetic substrates is around 7.0. Inhibition studies show that the protease is not inhibited by pepstatin nor by p-chloromercuribenzoic acid, indicating, respectively, that it is not an aspartyl protease nor a thiol protease. Complete inhibition is observed, however, with phenylmethanesulfonyl fluoride. Three crystal forms suitable for high resolution x-ray diffraction studies have been obtained from this purified protease with reflections being observed to well beyond 3.0 A resolution. One form having a needle morphology is of the orthorhombic crystal class and has space group P2(1)2(1)2(1). The unit cell dimensions are a = 41.9 A, b = 43.2 A, and c = 111.5 A with 1 molecule of the protease occurring in the asymmetric unit. The second form grown at pH values less than 6.0 has a plate morphology, is of orthorhombic space group P2(1)2(1)2(1), and has unit cell dimensions a = 59.12 A, b = 62.33 A, and c = 70.62 A. The third form is polyhedral in habit, is also of space group P2(1)2(1)2(1), and appears when the pH of the mother liquor is greater than 7.0. The cell dimensions of this crystal form are a = 57.07 A, b = 58.82 A, c = 70.79 A, and again there is 1 molecule/asymmetric unit. Three-dimensional structural analysis by x-ray diffraction is now underway. All crystal forms are somewhat denser than the norm having mass to volume ratios of 1.58, 2.00, and 1.85 A3/dalton, respectively.  相似文献   

11.
Lipase, an enzyme that hydrolyzes triacylglycerol, has been purified and characterized. The purification procedure includes ethanol precipitation and chromatographies on Sephacryl-200 HR, high resolution anion-exchange (mono Q) and Polybuffer exchanger 94. With this procedure, two forms of lipases from Geotrichum candidum were obtained. Lipase I (main enzyme) and lipase II (minor enzyme) were purified 35-fold with a 62% recovery in activity and 94-fold with a 18% recovery in activity, respectively. Their molecular weights have been estimated by polyacrylamide gel electrophoresis under denaturing conditions and by molecular sieving under native conditions at 56,000. Lipase I and II had optimum pH values of 6.0 and 6.8 and isoelectric points of 4.56 and 4.46, respectively. The enzymes are stable at a pH range of 6.0 to 8.0. Monovalent ions had little effect on both enzyme activities, while divalent ions at concentrations above 50 mM inhibited the lipase activities in a concentration-dependent manner. Sodium dodecyl sulfate at a concentration lower than 10 mM completely inhibited the lipase activity.  相似文献   

12.
The localization of lipase in cells of the fungus Penicillium cyclopium was investigated. It was shown by differential centrifugation of a homogenate of mycelial cells that the activity of the enzyme is associated with the cell wall. A study of ultrathin sections of mycelium fixed using the method of Zvyagintseva in an electron microscope showed that the final products of lipolytic activity of the enzyme is localized on the cell wall. Antibodies were raised against the purified A and B lipases from P. cyclopium and their specificity was assessed by enzyme-linked immunosorbent assay. The antibody preparation was used in cytochemical investigation by immunogold labelling. This study permits the localization of cell-bound lipase mainly in the cell wall and in the periplasmic space. The identity of the cell-bound lipase with one of the two extracellular lipases is also demonstrated.  相似文献   

13.
An extracellular protease from Penicillium chrysogenum (Pg222) isolated from dry-cured ham has been purified. The purification procedure involved several steps: ammonium sulfate precipitation, ion-exchange chromatography, filtration, and separation by high-performance liquid chromatography. Based on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis and gel filtration, the purified fraction showed a molecular mass of about 35 kDa. The hydrolytic properties of the purified enzyme (EPg222) on extracted pork myofibrillar proteins under several conditions were evaluated by SDS-PAGE. EPg222 showed activity in the range of 10 to 60 degrees C in temperature, 0 to 3 M NaCl, and pH 5 to 7, with maximum activity at pH 6, 45 degrees C, and 0.25 M NaCl. Under these conditions the enzyme was most active against tropomyosin, actin, and myosin. EPg222 showed collagenolytic activity but did not hydrolyze myoglobin. EPg222 showed higher activity than other proteolytic enzymes like papain, trypsin, and Aspergillus oryzae protease. The N-terminal amino acid sequence was determined and was found to be Glu-Asn-Pro-Leu-Gln-Pro-Asn-Ala-Pro-Ser-Trp. This partial amino acid sequence revealed a 55% homology with serine proteases from Penicillium citrinum. The activity of this novel protease may be of interest in ripening and generating the flavor of dry-cured meat products.  相似文献   

14.
15.
为建立圆弧青霉毒素-青霉酸的免疫学检测方法, 研究了青霉酸(PA)的人工抗原合成.通过碳二亚胺法将青霉酸(PA)分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)联结, 得到青霉酸人工抗原PA-BSA和PA-OVA.采用紫外扫描光谱法、SDS-PAGE和动物免疫试验对合成的抗原进行鉴定.结果显示联结后的人工抗原特征性吸收峰出现偏移, PA与BSA的偶联比为23.2:1, PA与OVA的偶联比为10.4:1.以PA-BSA为免疫抗原免疫小鼠, PA-OVA为包被抗原, 采用间接ELISA检测抗血清, 其效价达到1:12 800.表明青霉酸的人工抗原已合成, 为建立有效的免疫检测方法提供了基础.  相似文献   

16.
为建立圆弧青霉毒素-青霉酸的免疫学检测方法, 研究了青霉酸(PA)的人工抗原合成。通过碳二亚胺法将青霉酸(PA)分别与牛血清白蛋白(BSA)和卵清蛋白(OVA)联结, 得到青霉酸人工抗原PA-BSA和PA-OVA。采用紫外扫描光谱法、SDS-PAGE和动物免疫试验对合成的抗原进行鉴定。结果显示联结后的人工抗原特征性吸收峰出现偏移, PA与BSA的偶联比为23.2:1, PA与OVA的偶联比为10.4:1。以PA-BSA为免疫抗原免疫小鼠, PA-OVA为包被抗原, 采用间接ELISA检测抗血清, 其效价达到1:12 800。表明青霉酸的人工抗原已合成, 为建立有效的免疫检测方法提供了基础。  相似文献   

17.
利用生物信息学软件对GenBank上登录的圆弧青霉PG37碱性脂肪酶(LipⅠ)进行预测和分析。结果表明,PG37LipⅠ全肽含多个疏水区域,无明显跨膜结构域,定位于胞外,N-末端20个氨基酸为信号肽;PG37LipⅠ成熟肽是等电点为6.16的疏水性稳定蛋白质,包含一个Lipase_3的结构域,属于α/β水解酶超家族,含磷酸化位点等多种功能性位点,具有脂肪酸代谢的功能;α-螺旋和不规则卷曲是其蛋白质二级结构的主要结构元件,在三级结构中,Ser132-Asp188-His2413个氨基酸残基组成酶活性中心。  相似文献   

18.
19.
Aims:  The objective of this work was to investigate the lipase production by a newly isolated Penicillium sp . , using experimental design technique, in submerged fermentation using a medium based on peptone, yeast extract, NaCl and olive oil, as well as to characterize the crude enzymatic extracts obtained.
Methods and Results:  Lipase activity values of 9·5 U ml−1 in 96 h of fermentation was obtained at the maximized operational conditions of peptone, yeast extract, NaCl and olive oil concentrations (g l−1) of 20·0, 5·0, 5·0 and of 10·0 respectively. The partial characterization of crude enzymatic extract obtained by submerged fermentation showed optimum activity at pH range from 4·9 to 5·5 and temperature from 37°C to 42°C. The crude extract maintained its initial activity at freezing temperatures up to 100 days.
Conclusions:  A newly isolated strain of Penicillium sp . used in this work yielded good lipase activities compared to the literature.
Significance and Impact of the Study:  The growing interest in lipase production is related to the potential biotechnological applications that these enzymes present. New lipase producers are relevant to finding enzymes with different catalytic properties of commercial interest could be obtained, without using genetically modified organisms (GMO).  相似文献   

20.
Pectin lyase A (molecular weight 38 kD by SDS-PAGE, pI 6.7) was purified to homogeneity from culture broth of the mycelial fungus Penicillium canescens using chromatographic techniques. During genomic library screening, the gene encoding pectin lyase A from P. canescens (pelA) was isolated and sequenced, and the amino acid sequence was generated by applying the multiple alignment procedure (360 residues). A theoretical model for the three dimensional structure of the protein molecule was also proposed. Different properties of pectin lyase A were investigated: substrate specificity, pH- and temperature optimum of activity, stability under different pH and temperature conditions, and the effect of Ca2+ on enzyme activity. In the course of the laboratory trials, it was demonstrated that pectin lyase A from P. canescens could be successfully applied to production and clarification of juice.  相似文献   

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