PANCREATIC SPASMOLYTIC POLYPEPTIDE (PSP) .1. PREPARATION AND INITIAL CHEMICAL CHARACTERIZATION OF A NEW POLYPEPTIDE FROM PORCINE PANCREAS
PANCREATIC SPASMOLYTIC POLYPEPTIDE (PSP) .1. PREPARATION AND INITIAL CHEMICAL CHARACTERIZATION OF A NEW POLYPEPTIDE FROM PORCINE PANCREAS
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DOI：
10.1016/0167-0115(82)90126-4
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发表时间：
1982-01-01
影响因子：
--
通讯作者：
JACOBSEN, HE
中科院分区：
文献类型：
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作者：
JORGENSEN, KH;THIM, L;JACOBSEN, HE
在猪胰岛素的分离纯化中，发现了一种新的胰腺痉挛解肽（PSP）。采用沉淀、阴离子交换和阳离子交换色谱相结合的两种不同纯化方法制备了PSP。获得的最高产量为52 mg PSP/kg胰腺，表明猪胰腺中PSP的含量约为胰岛素含量的一半。通过基本圆盘电泳、等电聚焦、分析凝胶过滤和对胰腺中已知的各种多肽的放射免疫测定来判断，这两种制剂似乎都是非常纯的。PSP分子含有106个氨基酸（分子量约为11,700）。PSP是一种酸性（等电点，4.4），无游离n端氨基的非糖基化蛋白，脯氨酸和胱氨酸含量高。高含量的S-S桥（7个/分子），凝胶过滤测定的低表观分子量，以及对胰蛋白酶和凝乳胰蛋白酶处理的显著抗性，表明PSP分子结构紧凑。
A novel polypeptide, named pancreatic spasmolytic polypeptide (PSP), was discovered in a side-fraction from the purification of porcine insulin. PSP was prepared by 2 different purification methods based on combinations of precipitations, anion-exchange and cation-exchange chromatography. The highest yield obtained, 52 mg PSP/kg pancreas, indicates that the ocntent of PSP in porcine pancreas is about half the content of insulin. Both preparations appeared to be very pure as judged by basic disc electrophoresis, isoelectric focusing, analytical gel filtration and radioimmunoassays for various polypeptides known to be present in pancreas. The PSP molecule contains 106 amino acids (MW about 11,700). PSP is an acidic (isoelectric point, 4.4), non-glycosylated protein without free N-terminal amino groups, and with high contents of proline and cystine. The high content of S-S bridges (7/molecule), an unexpected low apparent MW determined by gel filtration, and a remarkable resistance towards treatment with trypsin and chymotrypsin, point to a compact structure of the PSP molecule.