Polymerization of pNcollagen I and copolymerization of pNcollagen I with collagen I. A kinetic, thermodynamic, and morphologic study.
Previous observations established that pNcollagen III copolymerized with collagen I and decreased the diameter of the fibrils formed (Romanic, A.M., Adachi, E., Kadler, K.E., Hojima, Y., and Prockop, D.J. (1991) J. Biol. Chem. 266, 12703-12709). Here, procollagen I alone or mixtures of procollagen I and pCcollagen I were incubated with procollagen C-proteinase to generate pNcollagen I or mixtures of pNcollagen I and collagen I. The results confirmed previous reports that pNcollagen I assembles into sheet-like structures. They also demonstrated that polymerization of pNcollagen I exhibits a lag period and propagation phase similar to those seen with other protein self-assembly systems. In addition, the results demonstrated that pNcollagen I formed true copolymers with collagen I in that the presence of pNcollagen I increased the lag time, decreased the propagation rate, and increased the concentration of collagen I in solution at equilibrium. Copolymerization of pNcollagen I with collagen I, however, differed in two features from copolymerization of pNcollagen III with collagen I. One was that, in confirmation of previous work, copolymerization of pNcollagen I with collagen I markedly altered the circularity of the fibrils formed. The second difference was that the copolymerization increased the concentration in solution at equilibrium of pNcollagen I whereas copolymerization with collagen I was previously shown to decrease the concentration in solution of pNcollagen III. The increase in concentration in solution of pNcollagen I was explicable either by the assembly of soluble oligomers of pNcollagen I and collagen I, or by subtle changes in the activities of pNcollagen I and collagen I in the solid-phase. Comparison with previous data with pNcollagen III indicated that although pNcollagen I and pNcollagen III copolymerize with collagen I, there are marked differences in the two kinds of copolymers.
Romanic
A M
AM
Department of Biochemistry and Molecular Biology, Jefferson Institute of Molecular Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
Adachi
E
E
Hojima
Y
Y
Engel
J
J
Prockop
D J
DJ
D003094:Collagen / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D017364:Collagenases; D004792:Enzyme Precursors / Q000378:metabolism; D005109:Extracellular Matrix / Q000648:ultrastructure; D066298:In Vitro Techniques; D007700:Kinetics; D003012:Microbial Collagenase / Q000378:metabolism; D008854:Microscopy, Electron; D011108:Polymers; D011347:Procollagen / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011498:Protein Precursors / Q000378:metabolism; D013816:Thermodynamics
D004792:Enzyme Precursors; D011108:Polymers; D011347:Procollagen; D011498:Protein Precursors; D003094:Collagen; D017364:Collagenases; C022440:procollagenase; D003012:Microbial Collagenase