Self-assembly of basement membrane collagen

PD Yurchenco, H Furthmayr - Biochemistry, 1984 - ACS Publications
PD Yurchenco, H Furthmayr
Biochemistry, 1984ACS Publications
Peter D. Yurchenco* and Heinz Furthmayr With the technical assistance of A. Coritz abstract:
The in vitro self-assembly of murine type IV collagen was examined by using biochemical
and morphological techniques. Dimeric collagen undergoes a rapid and reversible thermal
gelation at neutral pHwithout an appre-ciable lag period. The process is seen to be
concentration dependent and inhibited by 2 M urea. The formed complex can be visualized
by electron microscopy rotary shadowing as an irregular polygonal lattice network with …
Peter D. Yurchenco* and Heinz Furthmayr With the technical assistance of A. Coritz abstract: The in vitro self-assembly of murine type IV collagen was examined by using biochemical and morphological techniques. Dimeric collagen undergoes a rapid and reversible thermal gelation at neutral pHwithout an appre-ciable lag period. The process is seen to be concentration dependent and inhibited by 2 M urea. The formed complex can be visualized by electron microscopy rotary shadowing as an irregular polygonal lattice network with extensive side by side associations within the collagenous triple-helical part of the molecules, two and three strands thick. Measurements on the matrix suggest a median stagger dimension of 170 nm, Type IV collagen, a major component of basement mem-branes (Kefalides, 1973), is a structurally uniquecollagen (Bornstein & Sage 1980; Crouch et al., 1980; Heathcote et al., 1978; Minor et al., 1976; Trygvason et al., 1980) composed of two different types of constitutive chains. Basement membranes do not contain cross-striated fibers and, unlike the interstitial collagens, type IV collagen does not appear to form such fibers in vitro under physiologic salt conditions (Schwartz et al., 1980; Veis & Schwartz, 1981). This collagen possesses a number of distinct chemical features. The major triple-helical domain contains frequent interruptions of the regular collagenous Gly-XY triplet by sequences without this feature which are seen as flexible and protease-sensitive sites (Born-stein & Sage, 1980; Schuppan et al., 1980; Timpl et al., 1981; Hofmann etal., 1984). At the amino terminus of the tri-ple-helical monomer, there is a disulfide-rich domain of about 300 A which participates in binding to three other aminoterminal (N-terminal) 1 ends to produce a tetramer (Timpl et al., 1981; Kuhn et al., 1983; Duncan et al., 1983). The tetrameric domain has been isolated by proteolysis to yield a temperature-stable covalently cross-linked fragment with an apparent molecular weight of 200000-360000 and a Svedberg value of about 7 S (Risteli et al., 1980). At the C-terminal end of the molecule (Fessler & Fessler, 1982), there is a large globular domain with a molecular weight of about 75 000 (Timpl et al., 1981) which participates in bonding to the globular domain of another molecule. Using these two endregion bonds, it is possible to hypothesize an arrangement of type IV collagen in a two-and even three-dimensional matrix (Timpl et al., 1981).
ACS Publications