Zimmermann B, Damerau B, Vogt W
Hoppe Seylers Z Physiol Chem. 1980;361(6):915-24. doi: 10.1515/bchm2.1980.361.1.915.
Complement was activated in hog serum and the biologically active peptide(s) derived from the fifth component of complement were purified. Treatment of the serum with yeast, without any precautions to inhibit serum arginine carboxypeptidase, allowed the recovery of only one active fraction, the classical anaphylatoxin; it was identified as des-Arg-C5a. When hog serum was activated with yeast in the presence of 1M epsilon-aminohexanoic acid (inhibitor of arginine carboxypeptidase), two active C5-derived fractions were obtained, C5a and des-Arg-C5a. A partial amino acid sequence of the classical anaphylatoxin (19 N-terminal and 12 C-terminal amino acids) has been elaborated. With one exception it is identical with hog C5a as far as that structure is known (12 N-, 3 C-terminal amino acids). The only difference is the C-terminal region: arginine, present in C5a, is absent from des-Arg-C5a which ends with ... Asn-Ile-Gln-Leu-Gly-OH. The finding that des-Arg-C5a, virtually free of any significant contamination with C5a, has considerable spasmogenic activity demonstrates that it is the classical anaphylatoxin, and that for spasmogenic activity arginine as the C-terminal amino acid is not absolutely essential.
补体在猪血清中被激活，并且从补体第五成分衍生而来的生物活性肽被纯化。用酵母处理血清时，未采取任何抑制血清精氨酸羧肽酶的预防措施，仅回收了一种活性成分，即经典过敏毒素；它被鉴定为去精氨酸 - C5a。当猪血清在1M ε-氨基己酸（精氨酸羧肽酶抑制剂）存在下用酵母激活时，获得了两种源自C5的活性成分，C5a和去精氨酸 - C5a。已经阐明了经典过敏毒素的部分氨基酸序列（19个N端和12个C端氨基酸）。就已知结构而言（12个N端、3个C端氨基酸），除了一个例外，它与猪C5a相同。唯一的区别在于C端区域：C5a中存在的精氨酸在去精氨酸 - C5a中不存在，去精氨酸 - C5a以... Asn - Ile - Gln - Leu - Gly - OH结尾。几乎不含任何C5a显著污染的去精氨酸 - C5a具有相当大的致痉挛活性，这一发现表明它是经典过敏毒素，并且对于致痉挛活性而言，精氨酸作为C端氨基酸并非绝对必要。
