Further evidence for the correlation between the primary structure and the stain exclusion banding pattern of the segment-long-spacing crystallites of collagen

Abstract

Recently, we have noted the direct correlation between the primary structure of type I collagen and the electron microscopical banding pattern of the negatively stained segment-long-spacing (SLS) crystallites (K. Kobayashi, T. Ito, and T. Hoshino (1986), J. Electr. Microsc. 35, 272–275). In this paper, we examined the correlation in the other types of collagen. Unstained light bands (stain excluding bands) of the negatively stained SLSs of type II and type III collagens were located at the clusters of large hydrophobic amino acid residues along the respective molecules. Photographic averaging of the pattern improved the visual comparison of the correlation. We also noted a few occasions of discrepancy from the above-mentioned correlation. Preliminary computer simulation experiments revealed that, among amino acid parameters so far reported, only the hydrophobicity values of G. D. Rose and S. Roy (1980), Proc. Natl. Acad. Sci. USA 77, 4643–4647) explained the ability of amino acids for the negative staining (stain exclusion) of the collagen SLSs.