scholarly journals Robust chitinolytic activity of crab-eating monkey (Macaca fascicularis) acidic chitinase under a broad pH and temperature range

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maiko Uehara ◽  
Eri Tabata ◽  
Mikoto Okuda ◽  
Yukari Maruyama ◽  
Vaclav Matoska ◽  
...  

AbstractDiet of the crab-eating monkey (Macaca fascicularis) consists of both plants and animals, including chitin-containing organisms such as crabs and insects. This omnivorous monkey has a high expression of acidic chitinase (CHIA) in the stomach and here, we report on its enzymatic properties under different conditions. When we compared with Mus musculus CHIA (Mm-CHIA), Macaca fascicularis CHIA (Mf-CHIA) exhibits higher chitinolytic activity at broad pH (1.0–7.0) and temperature (30–70 ℃) range. Interestingly, at its optimum pH (5.0), Mf-CHIA showed the highest activity at 65 °C while maintaining it at robust levels between 50 and 70 °C. The degradation efficiency of Mf-CHIA was superior to Mm-CHIA toward both polymeric chitin as well as an artificial chromogenic substrate. Our results show that unique features of Mf-CHIA including its thermostability warrant the nomination of this enzyme for potential agricultural and biomedical applications.

1975 ◽  
Author(s):  
P. Friberger ◽  
G. Axelsson ◽  
K. Korsan-Bengtsen

Plasmin splits the chromogenic substrate B2-Phe-Val-Arg-pNA (S-2160, Bofors) at a relatively high rate. Standard plasmin in glycerol obtained from Nat. Inst, for Biol. Stand, and Contr., London, was tested in a system with Tris buffer of varying pH and ionic strength. The pH optimum for the reaction was found to be 7.4. Variations in ionic strength between 0.05–0.1 had insignificant influence but at higher ionic strength there was a slight inhibition. A linear relationship was found between plasmin and AOD/min. At optimum pH and a final substrate concentration of 0.2 mM 0.1 CTA unit corresponds to approximately 0.10 nkat. Purified plasminogen (AB Kabi, Stockholm, Sweden) in the concentrations 0.02–0.2 CU/ml was activated optimally with streptokinase (Kabikinase® ) in the concentrations 500–2000 IU/ml. Higher concentration gave inhibition. The activity of streptokinase activated plasminogen increased with a decreasing ionic strength. A linear relationship was found between streptokinase activated plasminogen and AOD/min. Approximately 3,000 Plong/units per ml of urokinase was needed to obtain the same activation as with optimal streptokinase concentration. The method has been used for determination of plasminogen in plasma. With final dilution of plasma in the range 1/20–1/200 activated by streptokinase (2000 IU/ml) in a system of pH 8.2, I = 0.05, a linear relationship was found between plasma dilution and AOD/min. The reproducibility in a series of tests is good (variation coefficient < 3%) and with insignificant interference by inhibitors. The determinations were easily carried out in a simple spectrometer (405 nm) and in an automatic reaction rate analyzer (LKB 8600, 410 nm).


2012 ◽  
Vol 518-523 ◽  
pp. 2653-2656
Author(s):  
Xiang Hua Feng ◽  
Liang Ding ◽  
Shi Min Ding

Photodegradation of dimethyl phthalate (DMP) in aqueous solutions by Fe(III)-pyruvate complex system was preliminarily investigated. The influences such as light sources, initial pH value, initial concentration of Fe(III), pyruvate and DMP on photodegradation efficiency of DMP were discussed in detail. The result indicates that DMP could be decomposed efficiently in Fe(III)-pyruvate system. The degradation efficiency of DMP are dependent on initial pH value, Fe (III) initial concentration and pyruvate initial concentration. The optimum pH for photodegration of DMP is 3.0. The degradation efficiency of DMP increases with increase of the initial concentrations of Fe(III) or pyruvate, whereas decreases with increase of the initial concentrations of DMP. Various light sources including metal halide lamps, daylight lamps, UV disinfection lamps and sunlight can be adopted in the system.


1974 ◽  
Vol 76 (3) ◽  
pp. 608-624 ◽  
Author(s):  
Kaoru Nozu ◽  
Bun-ichi Tamaoki

ABSTRACT Steroid Δ4-5α-hydrogenase was intracellularly localized in the nuclear and microsomal fractions of the rat ventral prostate (Nozu Sc Tamaoki 1973). The nuclear Δ4-5α-hydrogenase was found to have the following enzymatic properties essentially similar to the microsomal Δ4-5α-hydrogenase, with regard to the metabolism of [4-14C] testosterone in the presence of NADPH: The optimum pH of the enzymes in the two fractions was around 7.0 and the maximal conversion rates were obtained at a temperature of 35 to 40°C. The apparent Km values of the nuclear and microsomal Δ4-5α-hydrogenases were estimated respectively as 1.05 and 0.90 μmol/l, while the Km value of the hepatic microsomal Δ4-5α-hydrogenase was simultaneously estimated as 154 μmol/l. Among steroids, the most potent inhibitor group on the enzymatic 5α-hydrogenation of testosterone was Δ 4-3-oxo-C-21 steroids such as progesterone and 17α-hydroxyprogesterone, which were competitively converted into their 5α-hydrogenated metabolites in the highest rates. Among some anti-androgens, cyproterone and its acetate hardly inhibited the activities of the nuclear and microsomal enzymes, whereas etienic acid (4-androsten-3-one-17β-carboxylic acid), oestradiol-17β and diethylstilboestrol markedly inhibited both prostatic enzymes in a competitive manner. The Ki values of etienic acid, oestradiol-17β and diethylstilboestrol for the nuclear Δ4-5α-hydrogenase were respectively 1.50, 0.49 and 1.02 μmol/l, indicating similar affinities of these for the nuclear enzyme to that of testosterone.


2002 ◽  
Vol 68 (3) ◽  
pp. 1297-1304 ◽  
Author(s):  
C. Caldas ◽  
A. Cherqui ◽  
A. Pereira ◽  
N. Simões

ABSTRACT Xenorhabdus nematophila, a bacterium pathogenic for insects associated with the nematode Steinernema carpocapsae, releases high quantities of proteases, which may participate in the virulence against insects. Zymogram assays and cross-reactions of antibodies suggested that two distinct proteases were present. The major one, protease II, was purified and shown to have a molecular mass of 60 kDa and an estimated isoelectric point of 8.5. Protease II digested the chromogenic substrate N-tosyl-Gly-Pro-Arg-paranitroanilide (pNA) with V max and Km values of 0.0551 μM/min and 234 μM, respectively, and the substrate dl-Val-Leu-Arg-pNA with V max and Km values of 0.3830 μM/min and 429 μM, respectively. Protease II activity was inhibited 93% by Pefabloc SC and 45% by chymostatin. The optimum pH for protease II was 7, and the optimum temperature was 23°C. Proteolytic activity was reduced by 90% at 60°C for 10 min. Sequence analysis was performed on four internal peptides that resulted from the digestion of protease II. Fragments 29 and 45 are 75 and 68% identical to alkaline metalloproteinase produced by Pseudomonas aeruginosa. Fragment 29 is 79% identical to a metalloprotease of Erwinia amylovora and 75% identical to the protease C precursor of Erwinia chrysanthemi. Protease II showed no toxicity to hemocytes but destroyed antibacterial activity on the hemolymph of inoculated insects' larvae and reduced 97% of the cecropin A bacteriolytic activity.


1989 ◽  
Vol 54 (8) ◽  
pp. 2276-2286
Author(s):  
Tsezengijn Dash ◽  
Tomislav Barth ◽  
Jiřina Slaninová ◽  
Jana Barthová ◽  
Hana P. Mašková ◽  
...  

A reproducible method has been developed for the isolation of the adenohypophyseal enzyme with a trypsin-like activity. The enzyme is able to hydrolyze Nα-benzoyl-L-arginine-p-nitroanilide, a fluorogenic substrate CBzl-Arg-Arg-β-naphthyl amide and some peptides with one or two accumulated basic amino acids in the chain. The optimum pH for hydrolysis of the chromogenic substrate was within the range 6.0-7.0 (Km = 0.66 mmol l-1), in the case of the fluorogenic substrate the range was between 7.0 and 7.5 (Km = 1.2 μmol l-1). The enzyme is activated by cysteine and dithiothreitol and inhibited by SH-poisons. The molecular weight of the enzyme, determined by means of two independent methods, was approximately 25 kDA.


Sensors ◽  
2017 ◽  
Vol 17 (8) ◽  
pp. 1900 ◽  
Author(s):  
Anna A. Chlenova ◽  
Alexey A. Moiseev ◽  
Mikhail S. Derevyanko ◽  
Aleksandr V. Semirov ◽  
Vladimir N. Lepalovsky ◽  
...  

2011 ◽  
Vol 236-238 ◽  
pp. 1793-1798 ◽  
Author(s):  
Hua Zheng Liang ◽  
He Chen ◽  
Jian Feng Wang ◽  
Yu Lan He

Co-immobilize enzyme by cross-linking and embedding, optimize conditions for immobilizing, determinate the enzymatic properties of co-immobilized enzyme and study the methods for preparation of genipin using co-immobilized enzyme to hydrolyze geniposide. Optimized immobilizing conditions include glutaraldehyde concentration being 0.15%, cross-linking temperature being 20°C, cross-linking time being 2 hours, the activity of co-immobilized β-glucosidase and cell reaches to 65.33U/mg and the enzyme activity recovery being 52.63%. Enzymatic properties of co-immobilized enzyme are following: optimum temperature is 55°C and optimum pH is 5.0. The transformation experiments are carried out with co-immobilized enzyme. The results show that half-life of co-immobilized enzyme reaches around 40 days, higher than the normal immobilized enzyme. The conversion rate of geniposide is above 95% after 8 hours. The genipin is isolated, purified and recrystallized to reach more than 98% of purity by High Performance Liquid Chromatography. Advantages to prepare genipin using co-immobilized enzyme include low cost, high yield, environmental friendly and easy to manufacturing.


2012 ◽  
Vol 610-613 ◽  
pp. 404-408
Author(s):  
Xian Niu ◽  
Cheng Ding ◽  
Jin Long Yan ◽  
Bai Ren Yang

A dominant bacterium (LW13) for the degradation of chlorobenzene was selected from maturity sludge in a novel combined bio-filter polluted by chlorobenzene gas. Based on the morphological characteristics observation, physio-biochemical characteristics and 16S rDNA sequence homology analysis, strain LW13 was identified as Lysinibacillus fusiformis. Crude enzyme from the fermentation was extracted and their enzymatic properties were also investigated. Results showed that the degradation enzyme produced by the bacteria belong to extracellular enzymes. The purity of the enzyme was determined by SDS-PAGE gel electrophoresis and the molecular weight was found to be 52 kDa. The optimum pH value was about 8.0 with the optimum temperature of 45° C. Throughout the purification process, 85-fold of enzyme purification was achieved with the recovery of 20.69%.


1969 ◽  
Vol 56 (2) ◽  
pp. 171-180
Author(s):  
Lii-Jang Liu

Two strains of Colletotrichum spp., one dark and one light, were isolated from diseased fruits of guava in Puerto Rico. The isolates differ in cultural appearance, physiologic characteristics, and size of conidia. The optimum temperature range for mycelial growth of the dark strain lies between 24° and 28° C. The optimum temperature range for the light strain lies between 28° and 32° C. The optimum pH range for both strains lie between 5 and 7. Perithecia were produced when the dark strain was crossed with the light strain, or grown alone in potato dextrose agar at 24° to 28° C. Perithecia obtained from both isolates were typical of Glomerella cingulata. Ascospore isolations consistently resulted in the recovery of typical C. gloeosporioides cultures. Although conidia produced by the dark strain are significantly longer than those of the light strain, their perithecia are indistinguishable. Both strains are identified as C. gloeosporioides, the conidial stage of G. cingulata. The formation of the sexual stage of C. gloeosporioides in vitro in Puerto Rico has not been reported hitherto.


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