PROTEINS INVOLVED IN THE DEFENSE MECHANISMS OF HORSE SHOE CRABS

败血症是导致以下人群发病和死亡的主要原因 住院病人。尽管使用了强效的抗生素和 新生产的抗内毒素的单抗，死亡率仍在 很高。在目前的研究中，我们分离并表征了一种 具有凝集性、粘附性和抗菌性的蛋白质数量 马蹄蟹血清和变形细胞的活性。这个 使用离子交换和亲和层析的纯化方法 层析得到一种55 kDa的蛋白质，Limunectin，与 对革兰氏阳性和革兰氏阳性均有结合能力 阴性菌和细胞外基质。我们还确认了 一种具有特殊双重功能的12 kDa蛋白质；它与 内毒素，还含有蛋白水解酶抑制活性。凝血酶原， 凝块形成的底物，也有凝集活性 一旦它受到有限的蛋白质分解。我们正在进行 研究这种相互作用的性质和特殊性，并探索 这些成分和从其分离的其他成分的凝集素性质 蛙血。参与凝血级联反应的酶也是 调查过了。

Septicemia is a leading cause of morbidity and mortality among hospitalized patients. Despite the use of potent antibiotics and the newly produced monoclonal antibody against LPS, the mortality remains high. In the current studies we have isolated and characterized a number of proteins with agglutination, adhesion and antibacterial activities from the serum and the amebocytes of horseshoe crabs. The purification procedures using ion-exchange and affinity column chromatography resulted in a 55 kDa protein, limunectin, with the ability to bind to Limulus blood cells, to both gram positive and gram negative bacteria and to extracellular matrix. We have also identified a 12 kDa protein with unusual dual functional properties; it binds to endotoxin and also contains protease inhibitory activities. Coagulogen, the substrate for the clot formation, also has agglutinating activities once it is subjected to a limited proteolysis. We are in the process of studying the nature and specificity of such interactions and exploring the lectin properties of these and other components isolated from Limulus blood. Enzymes involved in the clotting cascade are also being investigated.