Abstract: | Abstract— The proteolipid and its partially delipidated protein from brain tissue have been studied by optical rotatory dispersion and circular dichroism in various solvents. The protein exhibits a helix content of 60–70 per cent in chloroform-methanol and 2-chloroethanol and is dextrorotatory in the visible region. In 1,1,1-trinuoroethanol, a higher helix content of 90 per cent is observed but the protein is laevorotatory. The helix content decreases in water and methanol with a much greater negative specific rotation in methanol. No random coil form has been observed. |