L-Aspartyl- 3-D-glucosylamine Amidohydrolases

4-L-Aspartyl-j8 D-glucosylamine Amidohydrolases.—The effect of various compounds on 4-L-aspartyl-j8-D-glucosylamine amidohydrolase (mol. wt. 6.3 X 10 ) from human liver has been studied. A-Acetyl-L-cysteine inhibited the enzyme non-competitively ( i 3,2 mM) whereas 3-hydroxybutanone inhibited competitively K 4.1 mM). l-Methionine, L-isoleucine, and cysta-thione enhanced enzyme activity. The differences between the characteristics of the enzymes from human and non-human sources were discussed. 

Whereas normally 4-L-aspartyl-jS-D-glucosylamine amidohydrolase is specific for substrates which contain both the free a-amino- and a-carboxy-groups of 

Cremonesi, R. Bovara, and G. Mazzola, Cellulose Chem. Technol., 1976, 10, 567. 

L-aspartic acid involved in the glycopeptide linkage, i.e. cannot act on glyco-peptides with several amino-acid residues, a new amidase which overrides these requirements has been discovered in almond emulsin. The enzyme was shown to cleave the glycopeptide linkage in the glycopeptide (16) from pineapple-stem bromelain. 

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