Molecular modeling study on a Leishmania cysteine proteinase

In this work, we propose the identification of structural motifs in the C-t erminal region of the Leishmania cysteine proteinase, a region that can cha racterize epitopes of human T cells, using molecular modeling calculations. Multiple sequence alignment and homology modeling were used to build a thr ee-dimensional model structure for the cysteine proteinase. With this theor etical proposition of three-dimensional structure, three distinct regions c an be assigned: alpha -helix regions (alpha (1), 224-232 CFDKNCTQGC; alpha (2), 240-253 ANECHKNGGGASM and alpha (3), 257-272 SPQKVTMCTYSNEFCV), two sm all strain regions (214-216 PAP and 237-239 LIK) being the major part of th e COOH-terminal region assigned as coils. The linear sequence of the COOH-t erminal region of the cysteine proteinase of Leishmania allows at least thr ee epitope regions, the structural motifs found corroborate this informatio n and encourages our experimental studies. (C) 2001 Elsevier Science B.V. A ll rights reserved.