Suzuki H, Parente A, Farina B, Greco L, La Montagna R, Leone E
Dipartimento di Chimica Organica e Biologica, Universita' di Napoli.
Biol Chem Hoppe Seyler. 1987 Oct;368(10):1305-12. doi: 10.1515/bchm3.1987.368.2.1305.
The complete amino-acid sequence of BS-RNAse, a dimeric ribonuclease isolated from bovine seminal plasma, was determined. The reduced and S-carboxymethylated subunit chain of the enzyme was cleaved by trypsin and chymotrypsin. The resulting peptides, purified by cation-exchange chromatography were sequenced by dansyl-Edman, subtractive Edman degradation and carboxypeptidase A and B digestion. Chymotryptic peptides were used for the alignment. Automated Edman degradation of the native protein, through the N-terminal 41 amino-acid residues, completed the sequence information. The subunit chain of BS-RNAse, composed of 124 amino-acid residues, with a molecular mass of 13,610 Da, is highly homologous (81%) to pancreatic ribonuclease A. A good degree of homology (31%) was also found with human angiogenin. No N-linked carbohydrate-attachment sites, such as Asn-X-Ser/Thr, were found in the protein.
已确定从牛精浆中分离出的二聚体核糖核酸酶BS-RNAse的完整氨基酸序列。该酶经还原和S-羧甲基化的亚基链用胰蛋白酶和胰凝乳蛋白酶进行切割。通过阳离子交换色谱法纯化得到的肽段，采用丹磺酰-埃德曼法、减法埃德曼降解法以及羧肽酶A和B消化法进行测序。胰凝乳蛋白酶切割得到的肽段用于序列比对。通过对天然蛋白质N端的41个氨基酸残基进行自动埃德曼降解，完善了序列信息。BS-RNAse的亚基链由124个氨基酸残基组成，分子量为13,610道尔顿，与胰腺核糖核酸酶A高度同源（81%）。与人类血管生成素也有较高的同源性（31%）。在该蛋白质中未发现如Asn-X-Ser/Thr这样的N-连接糖基化位点。
