PHYSICO-CHEMICAL STUDIES ON HAEMOLYSIN. PART V. ON THE COMPOSITION OF HAEMOLYSIN

The molecular weight of haemolysin has been determined to be 35,200 from diffusion experiments. The estimation of the different arniuo acids was carried out and it was found that the different amino acids like arginine, cysteine, histidine, lysine, methionine, tyrosine and tryptophane comprise 1/8, 1/9, 1/12, 1/24, 1/36 and 1/96 respectively of all the amino acid residues. On examining the ratio and the frequency of the different amino acids it is found that haemolysin molecule must contain at least 288 amino acid residues.

The minimum molecular weight of haemolysin as obtained by multiplying the number of amino add residues by its average residue weight (115.2 g.) is found to be 33,200.

The difference In molecular weight obtained by the two methods is thus about 4 per cent.