Mouse monoclonal antibodies for pneumolysin characterized.

2003 NOV 12 - (NewsRx.com & NewsRx.net) -- Researchers have characterized mouse monoclonal antibodies for pneumolysin.

"Pneumolysin (PLY) is a cholesterol-dependent cytolysin (CDC) produced by Streptococcus pneumoniae, the main cause of community-acquired pneumonia. We have applied a set of diverse molecular methodologies (PCR-derived PLY peptides, biopanning of a library of phage-displayed random nonapeptides, indirect ELISA and competition tests with soluble peptides) to achieve concordant complementary observations in order to obtain a fine epitope mapping of three mouse monoclonal antibodies (PLY-4, PLY-7 and PLY-8) for PLY," researchers in Spain report.

"PLY-4 seems to recognize a conformation-dependent epitope with a core reactivity involving R232," said Beatriz Suarez-Alvarez and colleagues at the University of Oviedo. "The epitopes recognized by PLY-7 and PLY-8 are within the sequences (401)GQDLTAH(407) and (450)KRTISIWGT(458), respectively. PLY-7 also recognizes suilysin (SLY), in which the homologous reactive amino acid stretch is (429)GVNLTSH(435). In a homology model of PLY with the crystal structure of perfringolysin 0 (PFO), R232 is part of a well-exposed contorted loop oil the edge of the concave and convex faces of domain 1."

"The sequences reactive with PLY-7 and PLY-8 would conform one of the loops at the bottom of domain 4 and a strand of one of the two sheets of this domain, respectively," reported the investigators. "Western blot analyses ...