人唾液蛋白質の生化学的研究(第9報) サリバ・パロチン・Aの化学試薬による分解および修飾とその生物活性におよぼす影響

抄録

Saliva-parotin-A was submitted to chemical cleavage with N-bromosuccinimide, performic acid, thioglycollic acid, or cyanogen bromide. The cleavage products were fractionated by Sephadex G-75 gel filtration, and the resultant fractions were assayed for hypocalcemic and leukocytosis-promoting activities. In most cases, the first peak possessed the biological activity. An active fraction (CNBr-I) from the cyanogen bromide cleavage product was tested for stability against heat, acid, and alkali, and for susceptability to chemical modifications with a variety of reagents. It was inferred that a histidine residue, or residues, might participate in the biological activities of CNBr-I. This fragment was a glycoprotein which contained 61.75% amino acid residues, 30.60% hexose, and 2.16% glucosamine. Its molecular weight was calculated to be 20000 by the Archibald method.