Glycosylasparaginase-catalyzed synthesis and hydrolysis of beta-aspartyl peptides.
beta-Aspartyl di- and tripeptides are common constituents of mammalian metabolism, but their formation and catabolism are not fully understood. In this study we provide evidence that glycosylasparaginase (aspartylglucosaminidase), an N-terminal nucleophile hydrolase involved in the hydrolysis of the N-glycosidic bond in glycoproteins, catalyzes the hydrolysis of beta-aspartyl peptides to form L-aspartic acid and amino acids or peptides. The enzyme also effectively catalyzes the synthesis of beta-aspartyl peptides by transferring the beta-aspartyl moiety from other beta-aspartyl peptides or beta-aspartylglycosylamine to a variety of amino acids and peptides. Furthermore, the enzyme can use L-asparagine as the beta-aspartyl donor in the formation of beta-aspartyl peptides. The data show that synthesis and degradation of beta-aspartyl peptides are new, significant functions of glycosylasparaginase and suggest that the enzyme could have an important role in the metabolism of beta-aspartyl peptides.
Department of Clinical Chemistry, Kuopio University Hospital, P.O. Box 1777, FIN-70211 Kuopio, Finland.
T
T
Noronkoski
I B
IB
Stoineva
I P
IP
Ivanov
D D
DD
Petkov
I
I
Mononen
D001224:Aspartic Acid / Q000737:chemistry*; D001227:Aspartylglucosylaminase / Q000378:metabolism*; D002384:Catalysis; D006868:Hydrolysis; D009842:Oligopeptides / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism
D009842:Oligopeptides; D001224:Aspartic Acid; D001227:Aspartylglucosylaminase