PRESSURE-DEPENDENCE OF COLLAGEN MELTING

Calf skin collagen type I and interstitial collagen of the annelids Al vinella pompejana and Riftia pachyptila were thermally unfolded at pre ssures of 1 and 200 bar. The high pressure was near the habitat pressu re of the annelids which live in deep sea hydrothermal vents. The tran sition temperature increased with pressure by only 1.4 +/- 1 degrees C for calf skin collagen, and no pressure effect was detectable for the annelid collagens. The value for calf skin collagen agrees with predi ction based on published values of the transition volume and transitio n enthalpy. The triple helices of the interstitial collagens of the an nelids, which have melting temperatures of 46 degrees C (Alivinella po mpejana) and 29 degrees C (Riftia pachyptila), are not further stabili zed by pressure.