Chitinase activity

In the present study, out of 22 Streptomyces strains, Streptomyces parvulus VCCM 22513 produced the highest chitinase activity. Time courses of incubation revealed that the maximum chitinase (0.91 ± 0.04 U/mL) of this strain was observed after 96 hours in the yeast extract salts medium supplemented with 10.0 g/L colloidal chitin.

10p dianmotminh02 03-05-2024 13 1   Download

The effect of some organic compounds on the activity of chitinase from Serratia marcescens has been investigated. Among these compounds, 1,10-phenanthroline was found to be an inhibitor and ethanol - an activator of the chitinase activity;
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’ dipyridyl and Zn2+ do not take any effect on the chitinase activity. In this investigation, the dissociation constant of an chitinase-metalic ion complex (K1) and the inhibition constant (K2) have been estimated with K1 = 0.1 mcM and K2 = 2.667 mM.

5p uocvong04 24-09-2015 39 4   Download

The role of chitosan in protection of soybean from sudden death syndrome caused by Fusarium solani f. sp. glycines has many contents: introduction, methods, fungal culture and growth, evaluation of the role of chitosan in protection of soybean from SDS development, chitinase activity assay in soybean leaves, statistical analysis, eVects of chitosan as a natural antifungal agenton inhibition of the radial and submerged growth ofF. solani f. sp. glycines,...

6p cscpubka 05-05-2014 88 2   Download

Hevamine is a chitinase from the rubber tree Hevea brasiliensis. Its active site contains Asp125, Glu127, and Tyr183, which interact with the )1 sugar residue of the substrate. To investigate their role in catalysis, we have successfully expressed wild-type enzyme and mutants of these residues as inclusion bodies in Escherichia coli. After refolding and purification they were characterized by both structural and enzyme kinetic studies. Mutation of Tyr183 to phenylalanine produced an enzyme with a lower kcat and a slightly higher Km than the wild-type enzyme.

9p research12 01-06-2013 48 4   Download

The enzymatic properties of chitinase A fromVibrio carchariaehave been studied in detail by using combined HPLC and electrospray MS. This approach allowed the separation ofaandbanomers and the simultaneous monitoring of chitooligosaccharide products down to picomole levels. Chi-tinase A primarily generated b-anomeric products, indicating that it cata-lyzed hydrolysis through a retaining mechanism.

11p fptmusic 11-04-2013 30 2   Download

The xylanase inhibitor protein I (XIP-I), recently identified in wheat, inhib-its xylanases belonging to glycoside hydrolase families 10 (GH10) and 11 (GH11). Sequence and structural similarities indicate that XIP-I is related to chitinases of family GH18, despite its lack of enzymatic activity. Here we report the identification and biochemical characterization of a XIP-type inhibitor from rice.

11p awards 06-04-2013 30 3   Download

Glycoside hydrolysis by retaining family 18 chitinases involves a catalytic acid (Glu) which is part of a conserved DXDXEsequence motif that spans strand four of a (ba)8 barrel (TIMbarrel) structure.Theseglycosidehydrolases are unusual in that thepositive charge emergingon theanomeric carbon after departure of the leaving group is stabilized by the substrate itself (the N-acetyl group of the distorted )1 sugar), rather than by a carboxylate group on the enzyme.

10p dell39 03-04-2013 34 3   Download

We present a comparative study of ChiA, ChiB, and ChiC, the three family 18 chitinases produced bySerratia marcescens. All three enzymes eventu-ally converted chitin to N-acetylglucosamine dimers (GlcNAc2) and a minor fraction of monomers. ChiC differed from ChiA and ChiB in that it initially produced longer oligosaccharides from chitin and had lower activ-ity towards an oligomeric substrate, GlcNAc6.

13p dell39 27-03-2013 44 3   Download

A novel elicitor that induces chitinases in tobacco BY-2 cells was isolated from Alternaria alternata102. Six other fungi, includingA. alternataIFO 6587, could not induce, or weakly induce chitinase activity. The purified elicitor was soluble in 75% methanol and showed the chitinase-inducing activity when applied at concentrations of as low as 25 ngÆmL )1 .

11p inspiron33 26-03-2013 36 5   Download

Chitotriosidase (CHIT1) is a chitinase that is secreted by activated macro-phages. Plasma chitotriosidase activity reflects the presence of lipid-laden macrophages in patients with Gaucher disease. CHIT1 activity can be con-veniently measured using fluorogenic 4-methylumbelliferyl (4MU)–chitotri-oside or 4MU–chitobioside as the substrate, however, nonsaturating concentrations have to be used because of apparent substrate inhibition.

11p viettel02 20-02-2013 27 1   Download

The hyperthermostable chitinase from the hyperthermophilic archaeon Pyrococcus furiosushas a unique multidomain structure containing two chi-tin-binding domains and two catalytic domains, and exhibits strong crystal-line chitin hydrolyzing activity at high temperature.

13p mobifone23 21-01-2013 37 4   Download

In this study Trichoderma atroviride was selected as over producer of chitinase enzyme among 30 different isolates of Trichoderma sp. on the basis of chitinase specific activity. From this isolate the genomic and cDNA clones encoding chit33 have been isolated and sequenced.

5p hongson039 30-05-2011 96 11   Download