Atomic force microscopy of intact and digested collagen molecules.
The present study was performed to analyse the structure of non-digested and digested collagen type I molecules by atomic force microscopy (AFM). Collagen type I molecules from the bovine skin were diluted with 0.05 N acetic acid, spread on a mica plate, air-dried and observed by non-contact mode AFM in air. Collagen molecules digested with Clostridium histolyticum collagenase were also examined by AFM. Intact collagen type I molecules were observed as twisted threads ranging mainly between 280 and 310 nm in length. The surface of the molecules was uneven and both ends usually slightly bulged like a globule. Depressions on the molecules were found throughout the length, and were most prominent approximately 70 nm from one end of the molecules. The collagenase-treated collagen molecules were degraded into fragments with various lengths, which corresponded to the data from sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The end of these fragments often appeared like a tuft, suggesting that the triple-helix unraveled at these regions.
Yamamoto
S
S
Department of Anatomy, Faculty of Medicine, Niigata University, Japan. shin@med.niigata-u.ac.jp
Nakamura
F
F
Hitomi
J
J
Shigeno
M
M
Sawaguchi
S
S
Abe
H
H
Ushiki
T
T
D000818:Animals; D002417:Cattle; D003094:Collagen / Q000378:metabolism / Q000648:ultrastructure*; D017364:Collagenases / Q000378:metabolism; D018625:Microscopy, Atomic Force; D010446:Peptide Fragments / Q000648:ultrastructure
D010446:Peptide Fragments; D003094:Collagen; D017364:Collagenases