Petsch D, Deckwer W D, Anspach F B
GBF, Gesellschaft für Biotechnologische Forschung, Bioverfahrenstechnik, Braunschweig, Germany.
Anal Biochem. 1998 May 15;259(1):42-7. doi: 10.1006/abio.1998.2655.
Cationic proteins, such as lysozyme, ribonuclease A, and human IgG, impaired the detection of endotoxins with the Limulus amebocyte lysate assay (LAL assay) through formation of endotoxin-protein complexes, demonstrating pronounced masking of endotoxins. Methods, such as phenol extraction, dilution heating, and perchloric acid treatment failed to demask the endotoxins. Also, digestion with trypsin, chymotrypsin, or pronase recovered only 10 to 20% of the applied endotoxins. However, endotoxin recoveries up to 100% were obtained with proteinase K digestion of the samples prior to the LAL assay. This method was then applied to examine the impact of endotoxin masking on endotoxin removal from protein solutions by selective adsorption on membrane adsorbers. It was found that poly-L-lysine and poly(ethyleneimine) as endotoxin-selective ligands were able to pull endotoxins off the proteins studied, thereby guaranteeing successful decontamination.
阳离子蛋白，如溶菌酶、核糖核酸酶A和人免疫球蛋白，通过形成内毒素-蛋白质复合物，干扰了鲎试剂法（LAL法）对内毒素的检测，表明内毒素有明显的被掩盖现象。诸如苯酚萃取、稀释加热和高氯酸处理等方法未能使内毒素去掩蔽。此外，用胰蛋白酶、糜蛋白酶或链霉蛋白酶消化只能回收所加入内毒素的10%至20%。然而，在进行LAL检测之前，用蛋白酶K消化样品可实现高达100%的内毒素回收率。然后将该方法应用于研究内毒素掩蔽对通过膜吸附剂选择性吸附从蛋白质溶液中去除内毒素的影响。结果发现，作为内毒素选择性配体的聚-L-赖氨酸和聚乙烯亚胺能够从所研究的蛋白质中去除内毒素，从而确保成功去污。
