Kanamori M, Doi H, Ideno S, Ibuki F
J Nutr Sci Vitaminol (Tokyo). 1981;27(3):231-41. doi: 10.3177/jnsv.27.231.
This paper describes the glycosylation sites of kappa-casein component P-5 from bovine mature milk. A short glycopeptide was prepared from kappa-casein component P-5 containing two carbohydrate chains by pronase P digestion, followed by gel filtration and ion exchange chromatographies. The glycopeptide obtained corresponded to residues 128-141 (Gly-Glu-Pro-Thr-Ser-Thr-Pro-Thr-Thr-Glu-Ala-Val-Glu-Ser) of kappa-casein A from the results of analyses with chemical and enzymatic procedures. The effect of alkaline borohydride treatment indicated the presence of serine as well as threonine as the binding site of carbohydrate moieties. From the facts of Edman degradation and carboxypeptidase P hydrolysis of glycopeptide treated with alkali, the carbohydrate moieties were considered to be attached to threonine residue No. 133 and serine residue No. 141.
本文描述了来自牛乳成熟乳的κ-酪蛋白组分P-5的糖基化位点。通过链霉蛋白酶P消化，接着进行凝胶过滤和离子交换色谱法，从含有两条碳水化合物链的κ-酪蛋白组分P-5制备了一种短糖肽。通过化学和酶促方法分析结果表明，得到的糖肽对应于κ-酪蛋白A的128 - 141位残基（甘氨酸-谷氨酸-脯氨酸-苏氨酸-丝氨酸-苏氨酸-脯氨酸-苏氨酸-苏氨酸-谷氨酸-丙氨酸-缬氨酸-谷氨酸-丝氨酸）。碱性硼氢化物处理的结果表明，丝氨酸以及苏氨酸是碳水化合物部分的结合位点。从对用碱处理的糖肽进行埃德曼降解和羧肽酶P水解的结果来看，碳水化合物部分被认为连接在第133位苏氨酸残基和第141位丝氨酸残基上。
