Cutfield J F, Cutfield S M, Carne A, Emdin S O, Falkmer S
Eur J Biochem. 1986 Jul 1;158(1):117-23. doi: 10.1111/j.1432-1033.1986.tb09728.x.
Insulin from the principal islets of the teleost fish, Cottus scorpius (daddy sculpin), has been isolated and sequenced. Purification involved acid/alcohol extraction, gel filtration, and reverse-phase high-performance liquid chromatography to yield nearly 1 mg pure insulin/g wet weight islet tissue. Biological potency was estimated as 40% compared to porcine insulin. The sculpin insulin crystallised in the absence of zinc ions although zinc is known to be present in the islets in significant amounts. Two other hormones, glucagon and pancreatic polypeptide, were copurified with the insulin, and an N-terminal sequence for pancreatic polypeptide was determined. The primary structure of sculpin insulin shows a number of sequence changes unique so far amongst teleost fish. These changes occur at A14 (Arg), A15 (Val), and B2 (Asp). The B chain contains 29 amino acids and there is no N-terminal extension as seen with several other fish. Presumably as a result of the amino acid substitutions, sculpin insulin does not readily form crystals containing zinc-insulin hexamers, despite the presence of the coordinating B10 His.
已分离并测序了鲇鱼（Cottus scorpius，即杜父鱼）主要胰岛中的胰岛素。纯化过程包括酸/醇提取、凝胶过滤和反相高效液相色谱，每克湿重胰岛组织可得到近1毫克纯胰岛素。与猪胰岛素相比，生物活性估计为40%。尽管已知胰岛中大量存在锌离子，但杜父鱼胰岛素在没有锌离子的情况下结晶。另外两种激素，胰高血糖素和胰多肽，与胰岛素一起被共纯化，并确定了胰多肽的N端序列。杜父鱼胰岛素的一级结构显示出一些在硬骨鱼中迄今为止独特的序列变化。这些变化发生在A14（精氨酸）、A15（缬氨酸）和B2（天冬氨酸）。B链含有29个氨基酸，并且没有像其他几种鱼类那样的N端延伸。推测由于氨基酸取代，尽管存在配位的B10组氨酸，但杜父鱼胰岛素不容易形成含锌胰岛素六聚体的晶体。
