Certain intermediary metabolites and the formation of fibrils from collagen solutions

The influence of certain intermediary metabolites of the aldehyde and benzoquinone type on the formation of collagen fibrils from a solution of an acid-soluble collagen (at 30° and pH 7.2) has been studied. Turbidimetric measurements made it possible to differentiate the nucleation process from the growth process during fibril formation with a reasonable degree of certainty. The increase in intermolecular cross-linkages results in a quicker and quantitatively increased formation of nucleation centers which determine the final characteristic of the fibrils. Among the aldehydes studied glutaraldehyde and acrolein were found to enhance the nucleation process most markedly, while formaldehyde and glyceraldehyde were less active. Of the benzoquinone derivatives homogentisic acid was highly effective, and gentisic acid was less effective. It can be concluded that these effective cross-linking agents are also involved in the formation of cross-linkages in connective tissues in vivo.