ABSTRACT
Sialic acids comprise a large family of N- and O-substituted neuraminic acid derivatives as components of glycoconjugates. N-Glycolylneuraminic acid is formed from N-acetylneuraminic acid by the action of the CMP-N-acetylneuraminic acid hydroxylase studied in various animals. O-Methylated sialic acids originate from the action of S-adenosylmethionine-8-O-methyltransferase studied in starfish. Sialic acids are O-acetylated at diverse positions by the action of acetyl-CoA-4-O- and -7-O-acetyltransferases found in various animals and, leading to the O-acetylation of sialic acid glycerol side chain, also in man. Some properties of these enzymes are described and biological implications discussed.
Subject(s)
Acetyl-CoA C-Acetyltransferase/metabolism , Acetylation , Animals , Humans , Methylation , Methyltransferases/metabolism , Mixed Function Oxygenases/metabolism , Molecular Structure , Sialic Acids/biosynthesis , Starfish/enzymologyABSTRACT
Os princípios utilizados na seleção das condições para medição são aqueles relacionados em publicações anteriores deste painel técnico (1). Soro foi usado como fonte de enzima. As concentrações selecionadas de substratos e o pH foram escolhidos com base em experimentos e em técnicas de otimização e foram confirmados por cálculos de equações de velocidade.