Coacervation of Solubilized Elastin effects a Notable Conformational Change

Abstract

WHEN fibrous elastin is rendered water soluble by partial hydrolysis the product, α-elastin, undergoes a temperature elicited coacervation which is readily reversible^1,2. Below room temperature α-elastin is soluble in dilute aqueous buffers in the region of its isoelectric point. On raising the temperature to 37° C a phase separation or coacervation occurs. In this communication we wish briefly to report that the circular dichroism pattern of soluble elastin most nearly resembles that of disordered proteins and polypeptides whereas the circular dichroism pattern of the coacervate (a mucilaginous precipitate) is characteristic of those obtained for the highly helical proteins and polypeptides. A calculation based on model polypeptides and myoglobin and on corrections for dampening of CD patterns due to absorption flattening and dispersion distortions³ implies an approximate 50 per cent α-helical content for the protein in the coacervate.