These results may be supported by the
fact that elastin is a strongly insoluble protein with enhanced
extraction by pepsin as confirmed by the greater amount of Cys
in the acid/pepsin fraction than in the other fractions (Table 2).
Disrupted structure of type I collagen fibrils may be due to a mutation
that causes substitution of cysteine for arginine (Arg134Cys)
on the pro-a1(I) chain (Beighton et al., 1988). In the present study,
reduced Cys levels in the FP coincided with a greater level of arginine
(Arg) in the insoluble fraction.