Isolation of alpha-amino adipic acid from mature dermal collagen and elastin. Evidence for an oxidative pathway in the maturation of collagen and elastin.

Human serum alpha-2-macroglobulin has been found to be a major cadmium-binding protein $\text{in vitro}$. Serum and alpha-2-macroglobulin equilibrated with cadmium at the 0.20 ppm level were chromatographed over Sephadex and agarose gels to separate and estimate the molecular weights of the proteins. Alpha-2-macroglobulin was found to fragment into reproducible fragments when chromatographed on agarose gels showing different metal-binding fractions for cadmium and endogenous zinc. The distribution of cadmium on serum protein chromatograms was correlated with alpha-2-macroglobulin chromatograms. Cadmium was bound to fractions with molecular weights as high as 800,000 daltons with an affinity greater than that observed for serum albumin.