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1.
Helmut Schübel Joachim Stckigt Richard Feicht Helmut Simon 《Helvetica chimica acta》1986,69(3):538-547
A novel highly substrate-specific Rauwolfia enzyme, raucaffricine β-D -glucosidase, was isolated from cell-suspension cultures of R. serpentina. The enzyme has been purified ca. 1350-fold, its major characteristics such as Mr = 66600 ± 5%, pH optimum 5.1, temperature optimum 38°, and inhibition of its activity by glucose and fructose were investigated. Its limited distribution in different cell cultures and differentiated plants indicates that the enzyme is present in significant amounts exclusively in cultured Rauwolfia cells. 相似文献
2.
Extracellular tyrosinase from Auricularia auricula RF201 was purified in a three-step procedure involving ammonium sulfate precipitation, Sephadex G-100, and DEAE-Sepharose column chromatography. The partially purified enzyme showed a single protein band of 12.6 kDa on SDS-PAGE. The optimum pH for tyrosinase activity was 7, and the enzyme was stable between pH 6 and 9. Tyrosinase has optimal activity at 40 °C and retained most of its activity between 4 and 50 °C. A. auricula tyrosinase could oxidize l-tyrosine, l-DOPA, catechol, and caffeic acid and displayed dark brown or peach color. However, the enzyme was unable to catalyze l-phenylalanine and ferulic acid. In comparison with other substrates, l-tyrosine displayed the highest affinity (K m of 0.11 mM) and the maximal reaction velocity (V max of 102.58 μmol/min). Tyrosinase activity was reduced in the presence of numerous tested compounds. Particularly SDS, it significantly inhibited enzyme activity. CuSO4 and NaCl showed an activation effect on enzyme activity, with the maximum activation found in the presence of CuSO4. 相似文献
3.
Nabil Smichi Ahmed Fendri Raja Chaabouni Faouzi Ben Rebah Youssef Gargouri Nabil Miled 《Applied biochemistry and biotechnology》2010,162(5):1483-1496
A lipolytic activity was located in the sardine digestive glands (pyloric caeca), from which a sardine digestive lipase (SaDL)
was purified. Pure SaDL has a molecular mass of 43 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis
analysis. The enzyme was found to be more active on short-chain triacylglycerols than on long-chain ones. SaDL does not present
the interfacial activation phenomenon. Control experiments were performed under the same experimental conditions, with dromedary
and turkey pancreatic lipases and showed a positive interfacial activation phenomenon. Sodium deoxycholate (NaDC) has an inhibitory
effect on the lipase activity. The pure enzyme lost 40% of its activity in presence of 8 mM NaDC. SaDL was found to be mostly
stable at low pH values. Interestingly, no colipase was detected in the sardine pyloric caeca. Analogous results were reported
for the scorpion and the crab digestive systems. This is in line with the idea that colipase might has evolved in mammal animals
simultaneously with the appearance of an exocrine pancreas. No similarity was found between the NH2-terminal amino acid residues of SaDL and those of lipases from the digestive tract of other species. Altogether, these results
suggest that SaDL is a member of a new group of lipases belonging to aquatic species. 相似文献
4.
A modified method has been developed to purify retine from pig liver. The crude extract of retine can be separated into five fractions by paper chromatography, each of them having been tested for the effect on the proliferation of protozoal Tetrahymena Pyriformis. One of the fractions, G3, has the strongest effect. The present results show that G3 fraction showed positive reactions toward 2,4-dinitro-phenyl hydrazine, ethylene diamine, and ninhydrin. Other properties of the fraction has also been studied. 相似文献
5.
Eltayib Hassan Ahmed Tripti Raghavendra Datta Madamwar 《Applied biochemistry and biotechnology》2010,160(7):2102-2113
A mesophilic bacterial culture producing a novel thermostable alkaline lipase was isolated from oil rich soil sample and identified
as Bacillus subtilis EH 37. The lipase was partially purified by ammonium sulfate precipitation and hydrophobic interaction chromatography with
17.8-fold purification and 41.9 U/ml specific activity. The partially purified enzyme exhibited maximum activity at pH 8.0
and at 60 °C. It retained 100% of activity at 50 °C and 60 °C for 60 min. The presence of Ca+2, Mg+2, and Zn2+ exhibited stimulatory effect on lipase activity, whereas Fe+3 and Co+2 reduced its activity. The enzyme retained more than 80% of its initial activity upon exposure to organic solvents, exhibited
107% and 115% activity in the presence of 15% isopropyl alcohol and 30% n-hexane, respectively. The EH 37 lipase also proved
to be an efficient catalyst in synthesis of ethyl caprylate in organic solvent, thus providing a concept of application of
B. subtilis lipase in non-aqueous catalysis. 相似文献
6.
Vinicius J. S. Osterne Mayara Q. Santiago Vanir R. Pinto-Junior João B. Cajazeiras Jorge L. A. Correia Cintia C. F. Leitão Rômulo F. Carneiro Francisco N. Pereira-Junior Mayron A. Vasconcelos Bruno A. M. Rocha Ana Maria S. Assreuy Pedro Henrique S. F. Bringel Celso S. Nagano Kyria S. Nascimento Benildo S. Cavada 《Applied biochemistry and biotechnology》2014,172(7):3342-3353
A novel mannose/glucose-binding lectin from Canavalia virosa (designated as ConV) has been purified from seeds of C. virosa by affinity chromatography on a mannose-Sepharose 4B column. ConV strongly agglutinates rabbit erythrocytes and was inhibited by monosaccharides (D-mannose, D-glucose, and α-methyl-D-mannoside) and glycoproteins (ovalbumin and fetuin). SDS-PAGE revealed three bands corresponding to three subunits (α, β, and γ) confirmed by ESI mass spectrometry with exact mass of 25,480?±?2 Da, 12,864?±?1 Da, and 12,633?±?1 Da, respectively. The purified lectin was more stable in pH ranging from 7.0 to 9.0, supported up to 80?ºC without any loss in activity and unaffected by EDTA. ConV showed no toxicity against Artemia sp. nauplii and relaxed endothelized rat aorta, with the participation of the lectin domain. In our tests, the lectin immobilized on CNBr-Sepharose was capable of binding 0.8 mg of ovalbumin per chromatography, allowing the use of ConV as a tool for capture and purification of glycoproteins. 相似文献
7.
Bao Zhang Chunjuan Dong Qingmao Shang Yuan Cong Weijia Kong Pinglan Li 《Applied biochemistry and biotechnology》2013,171(8):2262-2272
Bacillus amyloliquefaciens K103 isolated from a lemon sample was used as a biocontrol agent to suppress Rhizoctonia solani Kühn and other fungal plant pathogens. Two antifungal compounds were purified from the culture broth using acid precipitation, gel permeation chromatography, and reversed-phase high-performance liquid chromatography. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis indicated that the antifungal compounds were two isomers similar to bacillomycin L. One of the predominant active fractions was subjected to quadrupole time-of-flight mass spectrometry and amino acid analysis to determine its structural characteristics, revealing that the antifungal compound with a molecular mass of 1,034.5464 was identical to bacillomycin L. This is the second report of lemon microflora producing bacillomycin L or any antifungal compound, suppressing the growth of R. solani Kühn. Meanwhile, the study provided insights into the enormous potential of food microbial resources and bacillomycin L antibiotics in biological control and sustainable agriculture. 相似文献
8.
Abu-Khudir Rasha Salem Maha M. Allam Nanis Gamal Ali Ehab M. M. 《Applied biochemistry and biotechnology》2019,188(1):87-100
Applied Biochemistry and Biotechnology - (R)-[3,5-bis(trifluoromethyl) phenyl] ethanol [(R)-3,5-BTPE] is a crucial chiral intermediate for the synthesis of the NK-1 receptor antagonists aprepitant,... 相似文献
9.
Purification and Partial Characterization of (6-4) Photoproduct DNA Photolyase from Xenopus laevis 总被引:1,自引:0,他引:1
Sang-Tae Kim Khushbeer Malhotra John-Stephen Taylor Aziz Sancar 《Photochemistry and photobiology》1996,63(3):292-295
Abstract— The (6-4) photoproduct DNA photolyase was detected in two vertebrate animals Crotalus atrox (rattlesnake) and Xenopus laevis (South African clawed toad). The enzyme was extensively purified from X. laevis and characterized. The highly purified enzyme is fluorescent with an excitation maximum at 420-440 nm and emission maximum at 460-480 nm. The photorepair action spectrum matches the fluoresoence excitation spectrum with a 430 nm maximum. 相似文献
10.
Wenglong R. Lin Yulin Peng Scott Lew Claudia C. Lee Janet J. Hsu Jean-Francois Hamel Arnold L. Demain 《Tetrahedron》1998,54(52):1926-15925
Acetate kinase (EC 2.7.2.1), an enzyme involved in the wasteful production of acetate during conversion of cellulose to ethanol by Clostridium thermocellum, was purified 144-fold. The enzyme has an Mr of 84 kD by non-denaturing gradient gel electrophoresis, and an Mr of 46 kD when estimated with a denaturing gel; thus it appears to be a homodimer. Optimum enzyme activity occurs at 50°C and between pH 7.2 and 8.0. Acetate kinase is stable to temperatures up to 60°C, but is completely inactivated at 80°C after two h. The enzyme is stable between pH 7.0 and 9.0 when incubated at 50°C for two h. Optimum acetate kinase activity occurs at a MgCl2:ATP ratio of 2:1, which indicates an interaction between Mg2+ and ATP and that between Mg2+ and acetate kinase. Enzyme activity is partially inhibited by KCl, an inorganic salt frequently used in chromatography and fermentation media, losing 60% activity in the presence of 0.2 M KCl. Sigmoidal enzyme kinetics were observed from the velocity plot of acetate kinase when either the acetate (S0.5 = 285 mM) or ATP (S0.5 = 11 mM) concentration was varied, suggesting cooperative binding of the two substrates. 相似文献
11.
Purification and Characterization of an Antibacterial Peptide from Rana Temporaria Chensinensis Skin 总被引:1,自引:0,他引:1
GOU Xiao jun LI Xiang hui DING Tian bing WANG Yong ting CHEN Huai yong HUANG Cheng fang DONG Qing chu LI Qing shan * 《高等学校化学研究》1999,(4)
IntroductionInadditiontothehighlyspecificcell-mediatedimmunesystem,vertebratesandotherorganismshaveadefensesystemmadeupofdistinctgroupsofbroad-spectrumantibacterialpeptides[1—3].Antibacterialpeptidescanbeclassifiedintotwogroupsbasedonhavingdisul-fide… 相似文献
12.
13.
S. Coulon P. Chemardin Y. Gueguen A. Arnaud P. Galzy 《Applied biochemistry and biotechnology》1998,74(2):105-114
The lactic acid bacterium,Lactobacillus casei, produces an intracellular β-glucosidase when grown on Man-Rogosa-Sharpe (MRS) medium with cellobiose as carbon source. The
β-glucosidase activity is produced intracellulary, and no extracellulary activity was detected. The enzyme was purified by
ion-exchange chromatography and gel filtration. The molecular mass of the purified intracellular β-glucosidase as estimated
by gel filtration was 480 kDa, consisting of six probably identical subunits. The enzyme exhibited optimum activity at 35°C
and pH 6.3 with citrate-phosphate buffer. The enzyme was active against soluble glycosides with (1→4)-β configuration and
from Lineweaver Burk plots, Km value of 16 mmol/L was found for β-pNPG. The β-glucosidase was competitively inhibited by glucose, and no glycosyl transferase
activity was observed in the presence of ethanol. 相似文献
14.
Ji Hea Sung Sang Jung Ahn Na Young Kim Soo-Kyoung Jeong Joong Kyun Kim Joon Ki Chung Hyung Ho Lee 《Applied biochemistry and biotechnology》2010,162(3):900-911
An extracellular gelatinolytic enzyme obtained from the newly isolated Bacillus subtilis JB1, a thermophilic microorganism relevant to the aerobic biodegradation process of fish-meal production, was purified via
ammonium sulfate precipitation, Sephadex G-200 Gel filtration chromatography, and one-dimensional gel electrophoresis separation
and subsequently identified via peptide mass fingerprinting and chemically assisted fragmentation matrix-assisted laser desorption/ionization
time-of-flight mass spectrometry. The subtilisin JB1 gene was sequenced and its recombinant protein prosubtilisin JB1 was expressed in Escherichia coli, and the purified prosubtilisin JB1 (62 kDa) protein was digested with gelatin, bovine serum albumin, azocasein, fibrinogen,
and the fluorogenic peptide substrate Ala-Ala-Phe-7-amido-4-methylcoumarin hydrochloride, whereas the serine protease inhibitors
phenylmethylsulfonyl fluoride and chymostatin completely inhibited its enzyme activity at an optimal pH of 7.5. Thus, our
results show that subtilisin JB1 may serve as a potential source material for use in industrial applications of proteolytic
enzymes and microorganisms for fishery waste degradation and fish by-product processing. 相似文献
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16.
Muchtaridi Muchtaridi Rina Fajri Nuwarda Emmy Hainida Khairul Ikram Aisyah Saad Abdul Rahim Amirah Mohd Gazzali Habibah A. Wahab 《Molecules (Basel, Switzerland)》2022,27(3)
Neuraminidase (NA) is an enzyme that prevents virions from aggregating within the host cell and promotes cell-to-cell spread by cleaving glycosidic linkages to sialic acid. The best-known neuraminidase is the viral neuraminidase, which present in the influenza virus. Thus, the development of anti-influenza drugs that inhibit NA has emerged as an important and intriguing approach in the treatment of influenza. Garcinia atroviridis L. (GA) dried fruits (GAF) are used commercially as seasoning and in beverages. The main objective of this study was to identify a new potential neuraminidase inhibitor from GA. A bioassay-guided fractionation method was applied to obtain the bioactive compounds leading to the identification of garcinia acid and naringenin. In an enzyme inhibition study, garcinia acid demonstrated the highest activity when compared to naringenin. Garcinia acid had the highest activity, with an IC50 of 17.34–17.53 µg/mL or 91.22–92.21 µM against Clostridium perfringens-NA, and 56.71–57.85 µg/mL or 298.32–304.31 µM against H1N1-NA. Based on molecular docking results, garcinia acid interacted with the triad arginine residues (Arg118, Arg292, and Arg371) of the viral neuraminidase, implying that this compound has the potential to act as a NA enzyme inhibitor. 相似文献
17.
分离得到产抗菌聚氨基酸ε-聚赖氨酸菌株淀粉酶产色链霉菌TUST2, 从中纯化了ε-聚赖氨酸降解酶, 并对其性质进行了研究. 结果表明, 该酶为膜结合蛋白. 为提取该降解酶, 先收集菌体细胞并用超声波破碎, 细胞膜部分用1.0 mol/L NaSCN溶液溶解. 将粗酶液进行Sephadex G100凝胶柱层析分离. 用100 mmol/L磷酸缓冲液洗脱, 收集活性部分. 纯化后的样品用SDS-PAGE检测, 酶亚基分子量约为54700. 酶活力在pH=6.0~9.0间稳定, 最适宜pH=7.0. 酶的最适温度为30 ℃, 在10~50 ℃水浴30 min酶活力未见明显下降. 研究了不同金属离子对酶活力的影响, 结果表明, Zn2+, Cu2+和Fe3+可分别提高酶活力29.72%, 15.85%和15.08%; 但Ag+, Hg2+, Co2+和Mn2+对酶活力有强烈的抑制作用. Ca2+, K+和Ba2+对酶活力没有影响. 添加4%Tween-80能提高酶活力10%, 但EDTA能强烈抑制酶活力. 研究结果表明, 此降解酶的性质与白色链霉菌产生的ε-聚赖氨酸降解酶的性质相似. 相似文献
18.
Nan-di Zhou Xiao-lei Gu Xiao-hong Zha Ya-ping Tian 《Applied biochemistry and biotechnology》2014,172(1):351-360
Urethanase produced by Penicillium variabile was purified through ultrasonication, concentration by polyethylene glycol 20,000, and Superdex G-200 gel filtration chromatography. The molecular weight of urethanase was determined to be around 96 kDa by gel filtration. The purified enzyme showed a single band in SDS-PAGE with the molecular weight of ~13.7 kDa, which suggests that the enzyme has a multimeric structure composed of the same subunits. Peptide map fingerprinting analysis was then carried out by MALDI/TOF-TOF MS. Within the known sequences in NCBI, glucosamine-6-phosphate deaminase and 6-phosphogluconate dehydrogenase get high score as compared with urethanase. Sequence analysis informs that N-terminal sequence of urethanase is GTNTADNDAA. The Minchaelis constant (K m) and maximum reaction rate (V m) of urethanase are 27.2 mmol/L and 156.25 μmol/L min, respectively. 相似文献
19.
Marie Madeleine Giraud-Guille Gervaise Mosser Emmanuel Belamie 《Current Opinion in Colloid & Interface Science》2008,13(4):303-313
Collagens are unique triple helical proteins present in large quantities in a fibrillar form in tissues like tendon, bone, skin, cornea, where type I collagen predominates. The passage from triple helical molecules to fibrils obeys to controlled assembly properties, both in vitro by pH raise and in vivo through enzymatic control. The passage from individual fibrils to ordered fibrillar arrays could rely on self-assembly processes as suggested by the liquid crystalline properties of collagen. The present review considers this question recalling the liquid crystalline ordering properties of collagen or procollagen at high concentrations and the question of molecular packing within fibrils. The presence of alignments, undulations and twist at a suprafibrillar level will be described both from basic data in living tissues and recent experiments in self assembled materials. The possible link between laboratory experiences and biological processes will be discussed. 相似文献
20.
Sangeeta Yadav Pramod Kumar Yadav Dinesh Yadav Kapil Deo Singh Yadav 《Applied biochemistry and biotechnology》2009,159(1):270-283
An indigenously isolated fungal strain identified as Aspergillus terricola with assigned fungal strain number MTCC 7588 has been used as source for pectin lyase production. The extracellular pectin
lyase was purified to homogeneity from the culture filtrate of A. terricola by ion exchange and gel filtration chromatography. The determined molecular weight was 35 ± 01 kDa. The K
m and k
cat (turnover) values of the purified enzyme at 37 °C using citrus pectin as the substrate were found to be 1.0 mg/ml and 110.0 s−1, respectively. The pH and temperature optima of the enzyme were 8.0 and 50 °C, respectively. The retting ability of the purified
pectin lyase for natural fibers viz. Cannabis sativa and Linum usitatissimum has been demonstrated for the first time. 相似文献