EVIDENCE OF A LAMININ-BINDING PROTEIN ON THE SURFACE OF LEISHMANIA-DONOVANI

Both the promastigote and amastigote forms of the intracellular parasi te, Leishmania donovani bind the basement membrane glycoprotein lamini n with high affinity (K-d = 3.56 X 10(-9) M and 3.98 X 10(-9) M respec tively) with similar to 9000 and similar to 800 sites per cell. Bound laminin was identified by direct autoradiography and the binding prote in through analysis of the parasite extract by SDS-PAGE and immunoblot ting. A major component of 67 kDa was detected. The same protein was o btained when parasite outer membrane proteins were adsorbed to laminin -sepharose affinity matrix and subsequently eluted with SDS. The bindi ng affinity of the isolated receptor was similar to that of the whole cells. Such a receptor isolated in Leishmania for the first time, may function as one of the bridging molecules for extracellular matrix rec ognition. (C) 1996 Academic Press, Inc.