title: The reactivity of the disulphide bonds of wool.
abstract: 1. Fully reduced and S-carboxymethylated wool samples were prepared in which either the readily reducible cystine bonds or those that could only be reduced with difficulty were specifically labelled with iodo[2-(14)C]acetate; these two cystine fractions correspond to the (A+B) and (C+D) cystine fractions respectively, of Middlebrook & Phillips (1942). 2. Radioactively labelled peptides were isolated from partial acid hydrolysates of these wool samples. 3. It appears that the (A+B) cystine residues probably owe their increased reactivity to being in a more polar environment. 4. The implication of these results for the problem of characterizing the disulphide bonds of wool is briefly discussed.
mesh_terms: D000478:Alkylation; D000595:Amino Acid Sequence; D000818:Animals; D001345:Autoradiography; D002250:Carbon Radioisotopes; D002850:Chromatography, Gel; D002854:Chromatography, Paper; D003553:Cystine; D004220:Disulfides / Q000032:analysis*; D004590:Electrophoresis, Paper; D005612:Freeze Drying; D006868:Hydrolysis; D007461:Iodoacetates; D014935:Wool / Q000032:analysis*
chemical_list: D002250:Carbon Radioisotopes; D004220:Disulfides; D007461:Iodoacetates; D003553:Cystine