Protein crosslinkages: I. Effect of iodination on the time-dependent solubility changes of reconstituted collagen fibrils

Abstract

It has been shown that the iodination of tropocollagen leads to a more rapid formation of intermoleoular crosslinks of the reconstituted fibrils as judged by the inability to dissolve the fibrils in urea-HOAc solution. Iodination of the tropocollagen without subsequent fibril formation results in the formation of some intramolecular crosslinks as determined by ultracentrifugation at 40° and acrylamide gel electrophoresis and by the melting point and formation of segmented-long-spaced structures of the cooled gelatins derived therefrom. Control experiments and aminoacid analyses have shown that possible oxidation reactions cannot account for the changes. It is postulated that the iodination of histidine and/or tyrosine residues increases the rate of a normally occurring crosslinking reaction.