ABSTRACT
Penicillin-binding proteins (PBPs) were shown to associate non-covalently with many other morphogene proteins (MGPs). Specific associations were assigned. The PBPs were labeled with spectroscopic/fluorescence (F/S) groups in the form of dansylated β-lactam probes. Competitive β-lactam binding of non-denatured PBP/MGP complexes led to characteristic patterns of F/S labeling by the probes. The salt-bridge specific reagent, ethanedinitrile, covalently linked various MGPs to the F/S labeled PBPs. Proteolysis of chromatographically purified F/S labeled fractions gave sets of peptides analyzed by MALDI-TOF to give MH data. Peptide mass-fingerprinting analysis revealed that covalent linkage occurred with other MGPs and not with non-MGP proteins of ∼3400 proteins in the SWISS-PROT r33 data base for E. coli K-12.