A RECOMBINANT HOMOTRIMER OF TYPE-I PROCOLLAGEN THAT LACKS THE CENTRAL2 D-PERIODS - THE THERMAL-STABILITY OF THE TRIPLE-HELIX IS DECREASED BY 2 TO 4 DEGREES-C

A D-period cassette system was developed that can be used to synthesiz e a variety of recombinant homotrimers of type I procollagen. A constr uct lacking the central two D-periods of pro alpha 1(I) chains was ass embled and expressed as a recombinant protein in the mammalian cell li ne. The recombinant protein was purified to homogeneity and the therma l stability of the triple helix assayed by rapid protease digestion. T he results indicated that deletion of the central 468 amino acids from the major triple helix lowered the thermal stability of the protein b y 2 to 4 degrees C. The results therefore begin to define regions of t he molecule that vary in their contributions to helical stability.