INTERACTION OF COLLAGEN MAC ROMOL EC U L ES 



25 



bands in these regions is more conveniently obtained from observa- 

 tions on certain polymeric segment-type aggregates obtained from 

 solutions of collagen treated with sonic irradiation (see Fig. 4). It 

 is of interest that the two "fingerprints" thus obtained match each 

 other exactly in terms of the relative positions of the forty or so 



I 



Fig. 5. FLS-type fibril with an axial period of ca. 2800 A. The symmetrical 

 intraperiod band pattern corresponds with that expected for a packing of 

 protofibrils (linear polymers of TC) having no preferred polarization, i.e., in 

 antiparallel array, and with A-B junctions in approximate register. Stained 

 with PTA. X 33,000. (From Hodge, 1959b.) 



-^Sr« ^ «! • » 



-»^% 



Fig. 6. Polymeric SLS-type fibrils produced by addition of ATP to an acid 

 solution, of collagen at relatively high pH (co. 5). In this form, the linear 

 polymers of TC aggregate with all like features in register, (a) Stained with 

 PTA. (b) Stained with cationic uranium. X70,000. (From Hodge and Schmitt, 

 1960.) 



