Isolation and partial characterization of the carboxy-terminal propeptide of type II procollagen from chick embryos
Academic Article
Overview
Identity
Additional Document Info
Other
View All
Overview
abstract
The carboxy-terminal propeptide from type II procollagen was isolated from organ cultures of sternal cartilages from 17-day-old chick embryos. The procedure provided the first isolation Of the carboxy-terminal propeptide in amounts adequate for chemical characterization. The propeptide was isolated as a disulfide-linked trimer with an apparent molecular weight of about 100000. After reduction, monomers of about Mr 34000 were obtained. Antibodies were prepared to the propeptide and used to establish its identity. The antibodies precipitated type II procollagen but did not precipitate type II procollagen from which the amino- and carboxy-terminal propeptides were removed with pepsin. No collagen-like domain was found in the propeptide, and the amino acid composition was similar to that of globular proteins. The circular dichroism spectrum of the propeptide suggested the presence of -structure together with some random-coil structure. The data demonstrated that the type II carboxy-terminal propeptide is similar to the two different carboxy-terminal propeptides of type I procollagen in amino acid composition, molecular size, optical properties, and antigenicity. The homology among the type I and type II carboxy-terminal propeptides is consistent with the current hypothesis that they serve similar functions in vivo. The differences in structure may account for the selection of the appropriate proa chains to form the correct trimers in cells synthesizing several types of proa chains simultaneously. 1984, American Chemical Society. All rights reserved.
