An unusual collagen periodicity in skin.

The axial periodicity of collagen fibrils was observed by X-ray diffraction to be significantly shorter in wet skin (65.2 nm) than in wet tendon (67.0 nm). This difference appears to be due to some feature in the native skin environment, since purified skin Type I and Type III collagens will both form fibrils with a normal 67.0 nm d-period.