Oligosaccharide enzymic solubilization

It follows from the above that, if highly specific oligosaccharides need to be synthesized, glycosyltransferases [21] of the Leloir type [22] should be the enzymes of choice. These enzymes connect sugars via the activated nucleotide components with high stereo- and regioselectivity. They are substrate-specific, but, in vitro, with solubilized enzymes, it becomes possible to transfer modified donors to modified acceptors and thus broaden the scope of the synthetic applicability. 

The reason for these differences in properties between soluble and particulate enzyme was not elucidated. It may be postulated that the particles possibly contain two enzymes—one of these, stimulated by 2-acetamido-2-deoxy-D-glucose, is responsible for the synthesis of highly polymerized chitin, and the other catalyzes the synthesis of oligosaccharides only and does not require 2-acetamido-2-deoxy-D-glucose. If this hypothesis is correct, it would seem that the treatment with 1-butanol resulted in the solubilization of the second enzyme only. 

OST catalyzes an unusual reaction, rare in mechanistic enzymology, in which the nucleophilicity of the amide nitrogen of the asparagine residue must be enhanced to make a covalent bond with the oligosaccharide (see below). Before purified OST became available, basic biochemical characteristics of the enzyme were determined using microsomal membranes or detergent solubilized extracts. OST exhibits a requirement for divalent cations with a preference for Mn + over Mg + [15, 16, 27, 32-34]. The pH optimum of the enzyme is between 6.5 and 7.5 [15, 27, 34]. OST from different sources has been shown to be strongly stabilized by addition of phos-... 

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