Study of collagen denaturation kinetics by dynamic mechanical methods

✍ Scribed by S. Reich; J. Yonath

• Publisher: Wiley (John Wiley & Sons)
• Year: 1968
• Tongue: English
• Weight: 172 KB
• Volume: 6
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1968.360060711

✦ Synopsis

Study of Collagen Denaturation Kinetics by Dynamic Mechanical Met hods

Denaturation or melting of collagen fibers is accompanied by an appreciable contraction. It may occur as a fairly sharp transition upon heating the fiber or increasing the concentration of a contractile salt solution in which the fiber is immersed. Stretching force serves to increase the "melting temperature" or "melting concentration" and thus makes it possible for mechanical melting to occur by decreasing either the fiber's length or the force applied to it. The initial state in this type of melting is a stretched fiber equilibrated with a contractile salt solution.

Recently we studied this "mechanical" melting' and found that the force-length curves obtained at constant contraction rates are characterized by a transition region, in which probably the helix-coil transformation occurs.

In order to obtain better insight into a conceivable contractile mechanism, we followed the changes in dynamic mechanical properties of the collagen fiber which accompanied the denaturation process.

The collagen strips which were supplied hy I)r. J. Nicols, from Ethicon Inc., were cut from the smooth side of sheep suhmucose, cleaned in carbonate and EDTA, and then washed and dried. The strips used were 100 cm long and had approximately a circular cross section of 0.5 X 10-W.6 X Fiber length (1) is expressed in units of dry length, and the stretching force is referred to the dry cross-sectional area. All experiments were performed at room temperature, 26 f 0.5"C, and the contractile reagent used was a KCNS solution of 3.91 f 0.02M. 5. R. Meredith, 2% Mechanical Properties of Z'eztile Fihers, North Holland, Amsterdam, 1956.