Abstract
A crystalline protein has been isolated from fresh rubber latex (H. brasiliensis), for which the name hevein is proposed. This protein contains 5% S, has a molecular weight of approximately 10,000, a sedimentation constant of 1.19s at a concentration of 0.7%, and E1% at 280m/[mu] 25.6. Hevein contains 15 amino acids including cystine but no cysteine or methionine.