Enzymatic activities chitinasic

The studies mentioned and many others have used widely diverse methods of detecting hydrolytic activity on chitin (Table 1). Many note activity by disappearance of substrate v ile others focus on end product analysis. Both types offer advantages but often lack definitive results. Many techniques fail to separate products of chitinase from chitobiase activity or other polysaccharidases. In the present study an aquatic isolate, tentatively identified as CDC group EF-4a, was examined by various techniques to identify its chitinolytic ability and its use as a model of enzymatic activity in the environment. 

Chitin is the most abundant biomacromolecule in the animal field, which is found normally in invertebrates as a structural component. This important polysaccharide was synthesized for the first time by the enzymatic polymerization using chitinase and a chitobiose oxazoline derivative (Scheme 14).131 The latter activated monomer has a distorted structure with an a configuration at Cl, which resembles a transition-state structure of substrate chitin at the active site during a hydrolysis process (Scheme 15).3b 131132 The ring-opening polyaddition of the chitobiose oxazoline derivative was exclusively promoted by chitinase at pH 10.6, where the hydrolytic activity of chitinase was very much lowered. 

Monomer 7 synthesized via conventional organic technique, was subjected to the Bacillus sp. derived chitinase-catalyzed polymerization. Without enzyme, the monomer was gradually decomposed by non-enzymatic hydrolysis from aqueous media. In contrast, the ring opening reaction of oxazoline monomer was drastically activated by chitinase, giving rise to polymer 8 within 0.7 h. During the polymerization, the reaction mixture was kept homogeneous. 

Suginta, W., A. Vongsuwan, C. Songsiriritthigul, J. Svasti, and H. Prinz. 2005. Enzymatic properties of wild-type and active site mutants of chitinase A from Vibrio carchariae, as revealed by HPLC-MS. FEBS J. 111-. 3376-3386. 

Exo-chitinases have also been well studied. As an example, Kuk and colleagues have reported that two types of exo-chitinases (GlcNAc-ase and chitobiase) are associated with enzymatic preparation of Aeromonas sp. GJ-18. The activities of these enzymes are strongly influenced by the reaction temperature when swollen chitin was used as the substrate (Kuk et al. 2005). 

Aguilera, B., Ghauharali-van der Vlugt, K., Helmond, M.T. et al. 2003. Transglycosidase activity of chi-totriosidase Improved enzymatic assay for the human macrophage chitinase. J. Biol. Chem. 278 40911 0916. 

Sikorski, P., Sprbotten, A., Horn, S.J., Eijsink, V.G., and Varum, K.M. 2006. Serratia marcescens chitinases with tunnel-shaped snbstrate-binding grooves show endo activity and different degrees of processivity during enzymatic hydrolysis of chitosan. Biochemistry 45 9566-9574. 

Arakane, Y., H. Hoshika, and N. Kawashima et al. 2000. Comparison of chitinase isozymes from Yam tuber-enzymatic factor controlling the lytic activity of chitinases. Biosci. Biotechnol. Biochem. 64 723-730. 

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