The Proteins in Preserved Hevea Latex

Abstract

Abstract 1. Two proteins were isolated from preserved Hevea latex. 2. The proteins were distinguished by their electrokinetic behavior and their solubilities in aqueous solutions and in alcohol. Protein A has an isoelectric point at pH 4.55; it is insoluble in distilled water and alcohol. Protein B has an iso-electric point at pH 3.9; it is soluble in pure water and strong (70 per cent) alcohol. 3. A comparison of the electrophoretic mobility of the latex particles as function of the pH with the corresponding curves of the proteins confirms the result of previous investigators that a coating of the rubber particles by proteins is decisive for their behavior. In a range of pH between 5.5 and 8 the curve of the latex particles is practically identical with that of protein A.