Uncovering biphasic catalytic mode of C5-epimerase in heparan sulfate biosynthesis.
J Biol Chem
; 287(25): 20996-1002, 2012 Jun 15.
Article
in En
| MEDLINE
| ID: mdl-22528493
ABSTRACT
Heparan sulfate (HS), a highly sulfated polysaccharide, is biosynthesized through a pathway involving several enzymes. C(5)-epimerase (C(5)-epi) is a key enzyme in this pathway. C(5)-epi is known for being a two-way catalytic enzyme, displaying a "reversible" catalytic mode by converting a glucuronic acid to an iduronic acid residue, and vice versa. Here, we discovered that C(5)-epi can also serve as a one-way catalyst to convert a glucuronic acid to an iduronic acid residue, displaying an "irreversible" catalytic mode. Our data indicated that the reversible or irreversible catalytic mode strictly depends on the saccharide substrate structures. The biphasic mode of C(5)-epi offers a novel mechanism to regulate the biosynthesis of HS with the desired biological functions.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Carbohydrate Epimerases
/
Glucuronic Acid
/
Heparitin Sulfate
/
Iduronic Acid
Limits:
Humans
Language:
En
Journal:
J Biol Chem
Year:
2012
Document type:
Article
Affiliation country: