Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The binding of the outer membrane-disorganizing peptide polymyxin B nonapeptide (PMBN) to gram-negative bacteria was studied by using tritium-labeled PMBN. Smooth Salmonella typhimurium had a binding capacity of ca. 6 nmol of PMBN per mg (dry weight) of bacteria, which corresponds to ca. 1 X 10(6) to 2 X 10(6) molecules of PMBN per single cell. The binding was of relatively high affinity (Kd, 1.3 microM). The isolated outer membrane of S. typhimurium bound ca. 100 nmol of PMBN per mg of outer membrane protein (Kd, 1.1 microM), whereas the cytoplasmic membrane bound 9 to 10 times less. Other bacteria which are susceptible to the action of PMBN (Escherichia coli strains, Pseudomonas aeruginosa, Haemophilus influenzae) also bound large amounts of PMBN. The S. typhimurium pmrA mutant, Neisseria gonorrhoeae, and Proteus mirabilis (all known as resistant to polymyxin and PMBN) bound 3.3, 4, and 12 times less than S. typhimurium, respectively. The binding of PMBN to S. typhimurium was effectively inhibited by low concentrations of polymyxin B, compound EM49 (octapeptin), polylysine, and protamine. Spermine, Ca2+, and Mg2+ also inhibited the PMBN binding although they were ca. 160, 700, and 2,400 times less active (based on molarity) than polymyxin B, respectively. No binding inhibition was found at the tested concentrations of streptomycin, tetralysine, spermidine, or cadaverine.
 ...
PMID:Binding of polymyxin B nonapeptide to gram-negative bacteria. 298 30

Spermine at a concentration of 0.001 m initiated the reversion of penicillin-induced L-phase growth of Haemophilus influenzae to bacillary growth on penicillin L-phase medium. Reversion of L-phase colonies to bacillary colonies required 3 to 5 days. This spermine reversal of variant growth also occurred on penicillin induction medium in the presence of concentrations of tetracycline, erythromycin, and chloramphenicol that were not bactericidal for L-phase or bacillary inocula until 48 or more hr. Spermine was without protective effect against streptomycin and kanamycin, which were, in combination with penicillin, bactericidal at 24 hr. Spermine protection of L-phase variants against antibiotic toxicity was, therefore, related to initiation (by spermine) or bacillary growth from round bodies that survived for 24 or more hr at bacteriostatic levels of antibiotic.
 ...
PMID:Reversal of Penicillin-Induced L-Phase Growth of Haemophilus influenzae by Spermine and Its Effects on Antibiotic Susceptibility. 1655 61

Spermine reversal of penicillin-induced L phase of Haemophilus was found to be due to slow inactivation of penicillin by spermine. This inactivation was inhibited by sodium chloride. Cycloserine and cephalothin were also inactivated by spermine as demonstrated by reversal of L phase induced by these antibiotics. Spermine was inhibitory for growth of L phase induced by glycine. Spermidine and the diamines, putrescine and cadaverine, also interacted with penicillin, but very slowly and only at high molar ratios of polyamine to penicillin.
 ...
PMID:Reversal of L phase by slow inactivation of penicillin with polyamines. 1655 34