Rudman D, Chawla R K
J Pharmacol Exp Ther. 1976 May;197(2):402-7.
Preparations of the melanotropic-lipolytic peptide IIF from bovine choroid plexus contain 3% Ca, 1% Mg and less than 0.1% Na and K. Ca and Mg were removed by gel filtration on Sephadex G-10 in 1 N acetic acid. Capacity of the resulting cation-free peptide to bind Ca++, Mg++, Na+ and K+ was examined with the method of Hummel and Dreyer (Biochim. Biophys. Acta 63: 530-532, 1962). Peptide IIF bound a maximum of 3.7 to 4.4 mEq of Ca++, Mg++, Na+ or K+ per g of peptide. For each cation, linear Scatchard plot indicated one class of binding site. Association constants (liters per mole) were Ca++, 4.3 X 10(4); Mg++, 3.6 X 10(4); Na+, 4.8 X 10(2), K+, 1.9 X 10(2). Competitive binding experiments showed that all four cations occupied the same class of binding site.
从牛脉络丛中制备的促黑素 - 促脂肽IIF制剂含有3%的钙、1%的镁以及少于0.1%的钠和钾。通过在1N乙酸中用葡聚糖凝胶G - 10进行凝胶过滤去除钙和镁。用Hummel和Dreyer的方法（《生物化学与生物物理学学报》63: 530 - 532, 1962）检测所得无阳离子肽结合Ca++、Mg++、Na+和K+的能力。肽IIF每克肽最多结合3.7至4.4毫克当量的Ca++、Mg++、Na+或K+。对于每种阳离子，线性Scatchard图表明存在一类结合位点。缔合常数（升/摩尔）分别为：Ca++，4.3×10(4)；Mg++，3.6×10(4)；Na+，4.8×10(2)；K+，1.9×10(2)。竞争性结合实验表明，所有四种阳离子占据同一类结合位点。
