Marques M A, Mahapatra S, Sarno E N, Santos S, Spencer J S, Brennan P J, Pessolani M C
Laboratório de Hanseníase, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Av. Brasil, 4365, 21045-000 Rio de Janeiro, RJ, Brazil.
Braz J Med Biol Res. 2001 Apr;34(4):463-70. doi: 10.1590/s0100-879x2001000400004.
It has been demonstrated that the alpha2 chain of laminin-2 present on the surface of Schwann cells is involved in the process of attachment of Mycobacterium leprae to these cells. Searching for M. leprae laminin-binding molecules, in a previous study we isolated and characterized the cationic proteins histone-like protein (Hlp) and ribosomal proteins S4 and S5 as potential adhesins involved in M. leprae-Schwann cell interaction. Hlp was shown to bind alpha2-laminins and to greatly enhance the attachment of mycobacteria to ST88-14 Schwann cells. In the present study, we investigated the laminin-binding capacity of the ribosomal proteins S4 and S5. The genes coding for these proteins were PCR amplified and their recombinant products were shown to bind alpha2-laminins in overlay assays. However, when tested in ELISA-based assays and in adhesion assays with ST88-14 cells, in contrast to Hlp, S4 and S5 failed to bind laminin and act as adhesins. The laminin-binding property and adhesin capacity of two basic host-derived proteins were also tested, and only histones, but not cytochrome c, were able to increase bacterial attachment to ST88-14 cells. Our data suggest that the alanine/lysine-rich sequences shared by Hlp and eukaryotic H1 histones might be involved in the binding of these cationic proteins to laminin.
已经证明，施万细胞表面存在的层粘连蛋白-2的α2链参与麻风分枝杆菌附着于这些细胞的过程。在先前的一项研究中，为了寻找麻风分枝杆菌层粘连蛋白结合分子，我们分离并鉴定了阳离子蛋白组蛋白样蛋白（Hlp）以及核糖体蛋白S4和S5，它们是参与麻风分枝杆菌与施万细胞相互作用的潜在粘附素。结果显示，Hlp可结合α2-层粘连蛋白，并大大增强分枝杆菌对ST88-14施万细胞的附着。在本研究中，我们调查了核糖体蛋白S4和S5的层粘连蛋白结合能力。对编码这些蛋白的基因进行了PCR扩增，其重组产物在覆盖试验中显示可结合α2-层粘连蛋白。然而，在基于ELISA的试验以及与ST88-14细胞的粘附试验中进行测试时，与Hlp不同，S4和S5未能结合层粘连蛋白，也不能起到粘附素的作用。我们还测试了两种宿主来源的碱性蛋白的层粘连蛋白结合特性和粘附素能力，结果发现只有组蛋白能够增加细菌对ST88-14细胞的附着，而细胞色素c则不能。我们的数据表明，Hlp与真核H1组蛋白共有的富含丙氨酸/赖氨酸的序列可能参与了这些阳离子蛋白与层粘连蛋白的结合。
