Human PGRP-S binds to Lys-type and DAP-type PGNs. Purified rhPGRP-S or rdPGRP-LC (0.5 μg) were incubated with insoluble Lys-type or DAP-type PGN, and bound protein on the insoluble PGN was separated from unbound protein, as described in “Materials and methods.” One tenth of unbound protein (lane U) and one fifth of bound protein (lane B) were analyzed by Western blot analysis using anti-His(C-term) antibody. Molecular markers are indicated on the left.