Open AccessTwo penicillin binding proteins of Haemophilus influenzae are lost after cells enter stationary phase
Author(s) -
Mendelman Paul M.,
Chaffin Donald O.
Publication year - 1985
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1985.tb01118.x
Subject(s) - penicillin binding proteins , haemophilus influenzae , stationary phase , membrane , haemophilus , microbiology and biotechnology , bacterial growth , penicillin , biochemistry , biology , ampicillin , bacteria , chemistry , chromatography , antibiotics , genetics
The penicillin binding proteins (PBPs) of 4 representative isolates of Haemophilus influenzae were studied using crude membrane preparations and whole cells grown to the logarithmic and stationary phases of growth. Relative binding, % of total bound, and binding affinities were compared. The PBP patterns were similar for crude membranes and whole cells for all 4 strains tested at each phase of growth. However, PBP 2 was slightly reduced and PBP 4 was markedly reduced with whole‐cell labelling in comparison to crude membranes. 8 PBPs were detected in cells labelled during the logarithmic phase of growth, while 6 were detected in stationary phase cells. The pBPs ‘lost’ in stationary phase (PBPs 4 and 6) with apparent M r of 62 000 and 45 000, respectively, have a high affinity for ampicillin ( I 50 ≃ 0.04 μ g/ml). This suggests that these proteins may have an important role in cell growth, and are targets for β‐lactam substrates.