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Hydrolysis, racemization and absolute configuration of ureidoglycolate, a substrate of allantoicase

1970; Elsevier BV; Volume: 198; Issue: 3 Linguagem: Inglês

10.1016/0005-2744(70)90134-8

1878-1454

E. J. 's-Gravenmade, Godfried D. Vogels, Chris van der Drift,

Insect and Pesticide Research

1. A method is given for the accumulation and purification of (−)- and (+)-ureidoglycolate with the aid of allantoicase bound to Ecteola-cellulose. The optical rotation of these compounds was determiend as a function of pH, concentration and wavelength. From the sign of the Cotton effects at 208 and 228 mμ it was derived that (−)- and (+)-ureidoglycolate are S- and R-ureidoglycolate. 2. The rates of hydrolysis and racemization were studied as a function of pH; both reactions are susceptible to acid catalysis and the former reaction also to base catalysis. The results were compared with allantoate hydrolysis and glyoxylate hydration and a general reaction mechanism is suggested in which water and urea compete for the bonds in glyoxylate and allanturate. 3. The hydrolysis of ureidoglycolate is catalyzed by bivalent cations and phosphate ions. The complex formation was studied by the use of conductance measurements, electron paramagnetic resonance and infrared spectra. The mechanism of catalysis is discussed in view of the action mechanism of allantoicase.