1ojk: Difference between revisions

Revision as of 03:55, 3 May 2008

ANATOMY OF GLYCOSYNTHESIS: STRUCTURE AND KINETICS OF THE HUMICOLA INSOLENS CEL7BE197A AND E197S GLYCOSYNTHASE MUTANTS

OverviewOverview

The formation of glycoconjugates and oligosaccharides remains one of the most challenging chemical syntheses. Chemo-enzymatic routes using retaining glycosidases have been successfully harnessed but require tight kinetic or thermodynamic control. "Glycosynthases," specifically engineered glycosidases that catalyze the formation of glycosidic bonds from glycosyl donor and acceptor alcohol, are an emerging range of synthetic tools in which catalytic nucleophile mutants are harnessed together with glycosyl fluoride donors to generate powerful and versatile catalysts. Here we present the structural and kinetic dissection of the Humicola insolens Cel7B glycosynthases in which the nucleophile of the wild-type enzyme is mutated to alanine and serine (E197A and E197S). 3-D structures reveal the acceptor and donor subsites and the basis for substrate inhibition. Kinetic analysis shows that the E197S mutant is considerably more active than the corresponding alanine mutant due to a 40-fold increase in k(cat).

About this StructureAbout this Structure

1OJK is a Single protein structure of sequence from Humicola insolens. Full crystallographic information is available from OCA.

ReferenceReference

Anatomy of glycosynthesis: structure and kinetics of the Humicola insolens Cel7B E197A and E197S glycosynthase mutants., Ducros VM, Tarling CA, Zechel DL, Brzozowski AM, Frandsen TP, von Ossowski I, Schulein M, Withers SG, Davies GJ, Chem Biol. 2003 Jul;10(7):619-28. PMID:12890535 Page seeded by OCA on Sat May 3 03:55:39 2008

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OCA

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 [[Image:1ojk.jpg|left|200px]]
- {{Structure
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-}}
 '''ANATOMY OF GLYCOSYNTHESIS: STRUCTURE AND KINETICS OF THE HUMICOLA INSOLENS CEL7BE197A AND E197S GLYCOSYNTHASE MUTANTS'''
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 [[Category: Withers, S G.]]
 [[Category: Zechel, D L.]]
-[[Category: cellulose degradation]]
+[[Category: Cellulose degradation]]
-[[Category: glycosynthase]]
+[[Category: Glycosynthase]]
-[[Category: hydrolase]]
+[[Category: Hydrolase]]
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May  3 03:55:39 2008''
-''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 22:46:12 2008''