P-A-acetylhexosaminidase

Scheme 2 Hydrolysis mechanisms of retaining (A) and inverting (B) glycosidase and P-A-acetylhexosaminidase, which uses a modified retaining mechanism (C).

Scigelova M, Crout DHG. Microbial P-A-acetylhexosaminidases and their biotechnological applications. Enzyme Microb. Tech-nol. 1999 25 3-14. 

Kadowaki S, Saskiawan I, Watanabe J, Yamamoto K, Bunno M, Ichihara Y, Kumagai H. Transglycosylation activity of P-A-acetylhexosaminidase from Penicillium oxalicum and its application to synthesis of a drug carrier. J. Perm. Bioeng. 1997 83 341-345. 

Uzawa H, Zeng X, Minoura N. Synthesis of 6 -sulfodisaccharides by P-A-acetylhexosaminidase-catalyzed transglycosylation. Chem. Commun. 2003 34 100-101. 

Tay-Sachs disease can be diagnosed in the course of fetal development. Amniotic fluid is obtained by amniocentesis and assayed for P-A-acetylhexosaminidase activity. 

The vertebrate hyaluronidases, previously neglected enzymes [185], are all endo-P-A-acetylhexosaminidases employing substrate hydrolysis as their mechanism of action. These hydrolases have, until recently, been difficult to assay. Turbidometric and... 

Tay-Sachs disease A genetic disease that is a result of a deficiency in hexosaminidase A (P-A-acetylhexosaminidase), an enzyme that is involved in the degradation of ganghosides in the lysosome. The disease is prevalent in Jewish children of Eastern European descent and leads to a buildup of ganghoside in nerve cells of the brain and neuronal dysfunchon. 

C. Tay-Sachs disease is the result of the lack of the enzyme p-A-acetylhexosaminidase. Affected infants show weakness and retarded motor skills before 1 year of age. Other abnormalities follow, and death usually occurs before age 3. 

The synthesis of 2-acetamido-4-0-(2-acetamido-2-deoxy-P-D-galactopyranosyl)-2-deoxy-D-glucopyranose using P-A -acetylhexosaminidases from Asperigillus oryzae and Jack bean with a p-nitrophenyl activated donor [23] (Figure 12.8). 

Singh, S., R. Gallagher, P. J. Derrick, and D. H. G. Crout. 1995. Glycosidase-catalyzed oligosaccharide synthesis Preparation of the A-acetylchito-oligosaccharides penta-A/-acetylchitopentaose and hexa-Al-acetylchitohexaose using the P-A-acetylhexosaminidase of Aspergillus oryzae. Tetrahedron Asymm. 6 2803-2810. 

The transglycosylation activity and the reverse hydrolytic activity of A. oryzae P-A-acetylhexosaminidase have been used to synthesize A-acetylchitooligosaccharides... 

K. Yamashita, T. Ohkura, H. Yoshima and A. Kobata, Substrate specificity of diplococcal P-A-acetylhexosaminidase, a useful enzyme for the structural studies of complex type asparagine-linked sugar chain. Biochem. Biophys. Res. Commun., 1981,100, 226-232. 

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