Molecular properties sulfhydryl groups

Commercial-scale production of the high-molecular-weight tertiary mercaptans has yielded a number of products identified as tertiary dodecyl, tetradecyl, and hexadecyl mercaptans. Typical properties of these products are listed in Table 14-10. These tertiary mercaptans as a class undergo metal salt formation, oxidation to disulfides, and other known reactions of the sulfhydryl group. 

In addition to availability, crystalline papain has other properties which contribute to its importance in the field of enzymology. The molecular weight of papain is about 20,500, which is small enough to permit studies of the sequence of amino acids and the over-all structure by presently available chemical and enzymatic methods. The presence of one or more sulfhydryl groups which are concerned with the proteolytic activity gives some indication as to where to look for the active site of the enzyme. 

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