Increased Amount of Soluble Collagen by New Extraction Methods and its Relation to the Nature of Assocating Forces Among Collagen Molecules

About 50% of collagen in calf skin was solubilized by repeatedly changing the pH of an extraction medium from acid to neutral and neutral to acid and keeping temperature at 23°-25°C during acid extraction. This method is called 'pH relaxation extraction'.Addition of glucose (10%) to neutral buffer solubilized a large amount of collagen from calf skin.It was found that the collagen solubilized by these methods contained more β component than α and showed normal capability for fibril formation. The rate of fibril formation was higher than that of so-called acid soluble collagen. Amino and composition of the pH relaxation soluble collagen was little different from that of the acid soluble collagen.The mechanism of collagen solubilizatron by pH relaxation extraction is discussed in relation to the associating forces of insoluble collagen.