Calderon R O, Lujan H D, Aguerri A M, Bronia D H
Departamento de Bioquimica Clinica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Argentina.
Mol Cell Biochem. 1989 Apr 11;86(2):189-200. doi: 10.1007/BF00222619.
Human erythrocytes were fused by Trypanosoma cruzi from 7 and 14 day old culture (stationary and declination phases, respectively) while only lysis was induced by 4 day old culture parasite (exponential phase). Lysis and erythrocyte fusion were studied by phase contrast microscopy, measuring of hemolysis and gel electrophoresis. The fusogenicity is Ca2+-dependent while lysis is delayed in the absence of exogenous Ca2+. The proteolysis of erythrocyte protein bands 1, 2, 2.1, 2.3 and 3 are common features of both fusion and lysis processes. Nevertheless the breakdown rate of ankyrin (band 2.1) and band 3 are different in fused or in lysed cells. The lysis process is associated with a faster degradation of band 2.1 and increase of band 2.3 than in the case of the fusion process. By contrast, degradation of band 3 occurs faster in the fusion than in the lytic event. Treatment of fusogenic parasites but not erythrocytes with TPCK, soybean trypsin inhibitor or FCS inhibited to some extent the fusion process and the decrease of bands 1, 2, 2.1, 2.3 and 3. The results suggest that proteases from fusogenic parasites may be directly or indirectly involved in the proteolysis of band 2.1 in a way related to induction of fusion.
来自7日龄和14日龄培养物（分别为稳定期和衰退期）的克氏锥虫可使人类红细胞发生融合，而4日龄培养物的寄生虫（指数期）仅诱导红细胞裂解。通过相差显微镜、溶血测定和凝胶电泳研究了红细胞裂解和融合情况。融合活性依赖于Ca2+，而在没有外源Ca2+的情况下，裂解会延迟。红细胞蛋白带1、2、2.1、2.3和3的蛋白水解是融合和裂解过程的共同特征。然而，锚蛋白（带2.1）和带3在融合细胞或裂解细胞中的降解速率不同。与融合过程相比，裂解过程中带2.1的降解更快，带2.3增加。相比之下，带3在融合过程中的降解比裂解过程更快。用TPCK、大豆胰蛋白酶抑制剂或胎牛血清处理具有融合活性的寄生虫而非红细胞，在一定程度上抑制了融合过程以及带1、2、2.1、2.3和3的减少。结果表明，来自具有融合活性寄生虫的蛋白酶可能以与诱导融合相关的方式直接或间接参与带2.1的蛋白水解。
