A new method for the measurement of lipoprotein lipase in postheparin plasma using sodium dodecyl sulfate for the inactivation of hepatic triglyceride lipase.
A new method for the measurement of lipoprotein lipase in postheparin plasma using sodium dodecyl sulfate for the inactivation of hepatic triglyceride lipase.
复制标题
一种使用十二烷基硫酸钠灭活肝甘油三酯脂肪酶来测量肝素后血浆中脂蛋白脂肪酶的新方法。
作者：
M. Baginsky;W. Brown
脂蛋白脂肪酶（LPL）和肝甘油三酯脂肪酶（H-TGL）是在肝素后血浆中发现的脂解活性。本文介绍了一种简便、准确的直接测定肝素后血浆中LPL的方法。将该血浆与十二烷基硫酸钠（35 - 50 mM）在0.2 M Tris-HCl缓冲液（pH8.2）中预孵育（26 ℃下45- 60 min），导致H-TGL失活，同时使LPL完全活化。使用先前报告的不测量LPL的测定条件，在相同肝素后血浆样本的单独等分试样中直接测定H-TGL。抗十二烷基硫酸钠的脂解活性具有LPL的特征，这通过以下判断：a）其被血清和载脂蛋白C-II激活; B）其被0.75 M NaCl灭活（超过90%）;和c）其被特异性抗血清灭活。在LPL缺乏症（原发性I型高脂蛋白血症）患者的肝素后血浆中未发现十二烷基硫酸钠耐药活性。十二烷基硫酸钠处理后和H-TGL免疫灭活后测定的30个样品获得了极好的值相关性（r = 0.99）。值归一化前后的批内变异系数分别为+/- 11%和4%。
Lipoprotein lipase (LPL) and hepatic triglyceride lipase (H-TGL) are lipolytic activities found in postheparin plasma. A simple and precise method for the direct determination of LPL in postheparin plasma is described. Pre-incubations of this plasma (45--60 min at 26 degrees C) with sodium dodecyl sulfate (35--50 mM) in 0.2 M Tris-HCl buffer, pH 8.2, results in the inactivation of H-TGL, while leaving LPL fully active. Direct determination of H-TGL is done in a separate aliquot of the same postheparin plasma sample using previously reported assay conditons that do not measure LPL. The sodium dodecyl sulfate-resistant lipolytic activity has the characteristics of LPL as judged by a) its activation by serum and by apolipoprotein C-II; b) its inactivation (over 90%) by 0.75 M NaCl; and c) its inactivation by a specific antiserum. No sodium dodecyl sulfate-resistant activity was found in postheparin plasma from a patient with LPL deficiency (primary type I hyperlipoproteinemia). An excellent correlation of values was obtained (r = 0.99) for 30 samples assayed after sodium dodecyl sulfate treatment and after immuno-inactivation of H-TGL. The intra-assay coefficient of variation was +/- 11% and 4% before and after normalization of values, respectively.