Substrate specificity of mammalian intestinal dipeptidases and tripeptidases

Substrate specificity of mammalian pyridine nucleotide transglycosidases.

Spectrophotometrical analysis of pyridine nucleotide transglycosidase in mammalian tissues indicated that the enzyme activity was observed to be distributed ubiquitously among the mammalian tissues analyzed, although the velocity ratio of transglycosidation/hydrolysis (vT/vH) and the partitioning of nicotinic acid against water differed with the pyridine nucleotide substrate and the mammalian s...

Substrate specificity of mammalian prenyl protein-specific endoprotease activity.

We have previously identified proteolytic activity in rat liver microsomes that cleaves an intact tripeptide, VIS, from S-farnesylated-CVIS tetrapeptide. This enzymatic activity, termed prenyl protein-specific endoprotease (PPEP) activity, has been solubilized in CHAPS and purified 5-fold. To probe the peptide recognition features of PPEP activity, 64 tripeptides [N-acetyl-C(S-farnesyl)a1a2] we...

Structural Basis for Substrate Specificity of Mammalian Neuraminidases

The removal of sialic acid (Sia) residues from glycoconjugates in vertebrates is mediated by a family of neuraminidases (sialidases) consisting of Neu1, Neu2, Neu3 and Neu4 enzymes. The enzymes play distinct physiological roles, but their ability to discriminate between the types of linkages connecting Sia and adjacent residues and between the identity and arrangement of the underlying sugars h...

Substrate Specificity of MMPs

Substrate specificity and kinetic mechanism of mammalian G9a histone H3 methyltransferase.

Lysine-specific murine histone H3 methyltransferase, G9a, was expressed and purified in a baculovirus expression system. The primary structure of the recombinant enzyme is identical to the native enzyme. Enzymatic activity was favorable at alkaline conditions (>pH 8) and low salt concentration and virtually unchanged between 25 and 42 degrees C. Purified G9a was used for substrate specificity a...