A hypothesis as to mechanism of perturbation in biomembrane due to endotoxin. Participation of lysosomal cationic proteins with an endotoxin binding capacity

1)阳离子蛋白（CAP’s）的分级分离：通过0.1 M柠檬酸提取、乙醇沉淀和凝胶过滤步骤，通过FPLC从rebbit腹膜粒细胞中分级分离CAP’s。由于CAP’s能与肝素结合，因此我们正在研究用肝素琼脂糖凝胶纯化CAP’s。2）CAP’s能凝集LPS致敏的红细胞，尤其是Re-LPS致敏的红细胞（CAP-HA），CAP与LPS预孵育可抑制CAP-HA。浊度的增加取决于CAP-水平，尽管结合发生在CAP和LPS水平的最佳比例下;低离子强度和pH 6-7是CAP-HA的最佳条件;结合是可逆的。这似乎涉及CAP和LPS的离子和疏水结合。4）CAP对革兰氏阳性菌和革兰氏阴性菌的S型和R型均有抗菌活性，尤其对革兰氏阴性菌的R型抗菌活性最强。5）CAP与肝素结合后产生的溶血作用增加，从而中和了CAP和肝素的性质。6）一个小于10，000 M.W.的CAP组分。CAP具有较高的抗凝血活性。7）CAP能促进LPS的活性，使其与红细胞等细胞结合，并引起细胞膜的扰动。

1) Fractionation of cationic proteins (CAP's); CAP's were fractionated from rebbit peritoneal granulocytes through the steps of 0.1 M citric acid extraction, ethanol precipitation and gel filtration by FPLC. Since CAP's were capable of binding with heparin, a purification using heparin Sepharose is being investigated.2) CAP's agglutinated the erythrocytes sensitized with LPS, especially Re-LPS (CAP-HA); CAP-HA was inhibited by preincubation of CAP with LPS.3) CAP bound with LPS, especially Re-LPS in water solution, and made increased turbidity; the increase of turbidity depended upon CAP-levels, although the binding took place at an optimal ratio of both CAP and LPS levels; Low ionic strength condition and pH 6-7 were optimal to CAP-HA; the binding was reversible. This seems to be involved in both ionic and hydrophobic bounds of CAP and LPS. CAP-HA is thought to result from the binding mentioned above.4) CAP exhibited antibacterial activity against S and R form gram-negative bacteria as well as gram-positive bacteria, expecially against R from gram-negatives. The activity seems to be bacteriolytic.5) CAP bound with heparin made increased trubidity, consequently the binding neutralized mutually the properties of CAP and heparin.6) One CAP fraction of less than 10,000 M.W. had high anticoagulant activity compared to other properties.7) It seems that CAP can promote the activity of LPS, which bound with cells such as erythrocytes, and membrane perturbation.