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Role of the pro‐α2(I) COOH‐terminal region in assembly of type I collagen: Disruption of two intramolecular disulfide bonds in pro‐α2(I) blocks assembly of type I collagen
Author(s) -
Doyle Sharon A.,
Smith Barbara D.
Publication year - 1998
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/(sici)1097-4644(19981101)71:2<233::aid-jcb8>3.0.co;2-w
Subject(s) - cysteine , chemistry , procollagen peptidase , intramolecular force , disulfide bond , stereochemistry , protein disulfide isomerase , biochemistry , biophysics , enzyme , biology , microbiology and biotechnology
Collagen biosynthesis is a complex process that begins with the association of three procollagen chains. A series of conserved intra‐ and interchain disulfide bonds in the carboxyl‐terminal region of the procollagen chains, or C‐propeptide, has been hypothesized to play an important role in the nucleation and alignment of the chains. We tested this hypothesis by analyzing the ability of normal and cysteine‐mutated pro‐α2(I) chains to assemble into type I collagen heterotrimers when expressed in a cell line (D2) that produces only endogenous pro‐α1(I). Pro‐α2(I) chains containing single or double cysteine mutations that disrupted individual intra‐ or interchain disulfide bonds were able to form pepsin resistant type I collagen with pro‐α1(I), indicating that individual disulfide bonds were not critical for assembly of the pro‐α2(I) chain with pro‐α1(I). Pro‐α2(I) chains containing a triple cysteine mutation that disrupted both intrachain disulfide bonds were not able to form pepsin resistant type I collagen with pro‐α1(I). Therefore, disruption of both pro‐α2(I) intrachain disulfide bonds prevented the production and secretion of type I collagen heterotrimers. Although none of the individual disulfide bonds is essential for assembly of the procollagen chains, the presence of at least one intrachain disulfide bond may be necessary as a structural requirement for chain association or to stabilize the protein to prevent intracellular degradation. J.Cell. Biochem. 71:233–242, 1998. © 1998 Wiley‐Liss, Inc.