Jakob A, Hauri C, Froesch E R
J Clin Invest. 1968 Dec;47(12):2678-88. doi: 10.1172/JCI105951.
Total nonsuppressible insulin-like activity (ILA) of human plasma (measured by the adipose tissue assay) results from the additive effects of at least two distinct components. They differ in molecular size, solubility in acid-ethanol, and in thermostability. More than 90% of nonsuppressible ILA of human plasma is insoluble in acid-ethanol. Its molecular size of 100,000-150,000 remains unchanged by treatment with acid-ethanol, 5 M acetic acid-0.15 M NaCl, urea, and EDTA. It is inactivated by heat. Approximately 5% of total nonsuppressible serum ILA is soluble in acid-ethanol. The molecular weight is 6000-10,000 after partial purification on Sepadex G-75 (acetic acid-NaCl). This molecule is thermostabile for 3 hr at 80 degrees C. When the acid-ethanol soluble molecule with nonsuppressible ILA is chromatographed on Sephadex G-100 at neutral pH, it is eluted in a broad peak corresponding to a molecular weight of approximately 50,000-70,000. When rechromatographed on Sephadex G-75 (acetic acid-NaCl) its mol wt is irreversibly converted from 70,000 to 6000. Most of the insulin-like activity retained on Dowex-50 ("bound insulin") is eluted off Sephadex G-75 (acetic acid-NaCl) at the same column volume as the small molecular weight nonsuppressible ILA. The latter molecule is retained on Dowex-50, whereas big molecular weight nonsuppressible ILA is not.
人血浆中总的非抑制性胰岛素样活性（ILA，通过脂肪组织检测法测定）是由至少两种不同成分的累加效应产生的。它们在分子大小、在酸乙醇中的溶解度以及热稳定性方面存在差异。人血浆中超过90%的非抑制性ILA不溶于酸乙醇。其100,000 - 150,000的分子大小在用酸乙醇、5M乙酸 - 0.15M氯化钠、尿素和乙二胺四乙酸处理后保持不变。它会被加热灭活。总的非抑制性血清ILA中约5%可溶于酸乙醇。在葡聚糖凝胶G - 75（乙酸 - 氯化钠）上部分纯化后，其分子量为6000 - 10,000。该分子在80℃下3小时内具有热稳定性。当具有非抑制性ILA的酸乙醇可溶性分子在中性pH下于葡聚糖凝胶G - 100上进行色谱分析时，它以对应于约50,000 - 70,000分子量的宽峰形式被洗脱。当在葡聚糖凝胶G - 75（乙酸 - 氯化钠）上重新进行色谱分析时，其分子量不可逆地从70,000转变为6000。保留在Dowex - 50上的大部分胰岛素样活性（“结合胰岛素”）与小分子非抑制性ILA在相同柱体积下从葡聚糖凝胶G - 75（乙酸 - 氯化钠）上被洗脱下来。后一种分子保留在Dowex - 50上，而大分子非抑制性ILA则不然。
