Localization of the site of fixation of the inducer, penicillin, in Bacillus cereus

Duerksen, Jacob D.

doi:10.1016/0926-6550(64)90053-2

Cited by 16 publications

(27 citation statements)

References 30 publications

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“…The binding followed saturation type kinetics (specific binding), and its saturation was achieved at low concentration (2 nmol/ mil) of the antibiotic, as has been shown (16,26) for penicillin-susceptible organisms. However, the binding to whole cells of this organism was entirely of the nonsaturation type (nonspecific), although binding to penicillin-susceptible organisms was specific as previously desciKbed (4,5,8,15,20,24,26), and saturation was achieved at low concentration of penicillin G, as with the membrane fractions (16,17). About 3 nmol of penicillin G was specifically bound per g of the membrane protein at saturation.…”

Section: Discussionmentioning

confidence: 87%

“…However, the binding was entirely nonspecific. The amount bound to whole cells was directly proportional to the concentration up to a level of at least 750 nmol/ml, although binding to the membrane fraction from this organism and to the whole cells of penicillin-susceptible organisms was specific as described above and previously (4,5,8,15,20,24,26). The binding of [14C]benzylpenicilloic acid to the cells was also nonspecific and of lower affinity compared with penicillin G.…”

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confidence: 99%

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Penicillin-Resistant Mechanisms in Pseudomonas aeruginosa : Binding of Penicillin to Pseudomonas aeruginosa KM 338

Suginaka

Ichikawa

Kotani

1975

Antimicrob Agents Chemother

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A comparison of the binding of radioactive penicillin G to whole cells and the membrane fraction derived from Pseudomonas aeruginosa KM 338 was made. This organism has intrinsic resistance to penicillin. The binding to the membrane fraction which catalyzed peptidoglycan synthesis followed saturation type kinetics and saturation was achieved at approximately 2 nmol of penicillin G per ml, whereas binding to the whole cells was entirely of the nonsaturation type. The binding of carbenicillin to the membrane fraction was determined by competition between radioactive penicillin G and unlabeled carbenicillin for the binding sites. It was bound at the same sites in almost the same manner. When whole cells were pretreated with high concentration of unlabeled penicillin G or carbenicillin, the subsequent binding of radioactive penicillin G to the membrane fraction from carbenicillin-treated cells was entirely nonspecific, but with penicillin G-pretreated cells it was still specific. There was apparently specific binding of radioactive penicillin G to ethylenediaminetetraacetate-treated cells. P. aeruginosa KM 338 had an extremely low activity of β-lactamase compared with other enzyme-producing organisms. This enzyme from P. aeruginosa KM 338 was of the cephalosporinase type. These data indicate that penicillin resistance of P. aeruginosa KM 338 may be a consequence of the development of a permeability barrier which prevents the antibiotic from reaching its sites of action in the cytoplasmic membrane.

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Section: Discussionmentioning

confidence: 87%

mentioning

confidence: 99%

Penicillin-Resistant Mechanisms in Pseudomonas aeruginosa : Binding of Penicillin to Pseudomonas aeruginosa KM 338

Suginaka

Ichikawa

Kotani

1975

Antimicrob Agents Chemother

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“…Additionally, over 90% of cell-bound radiolabeled penicillin was released upon protoplast formation as a highmolecular-weight material (13). However, cells induced with penicillin before protoplast formation continued to produce P-lactamase (13). From such studies comes the notion that penicillin effects a stable or long-lived modification of the cell envelope which results in prolonged induction of Plactamase (9,10).…”

mentioning

confidence: 99%

“…Penicillin (34). Furthermore, it has been reported that protoplasts of B. cereus cannot be induced, nor can they bind radiolabeled penicillin (13). Additionally, over 90% of cell-bound radiolabeled penicillin was released upon protoplast formation as a highmolecular-weight material (13).…”

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confidence: 99%

Transcriptional analysis of beta-lactamase regulation in Bacillus licheniformis

Salerno¹,

Lampen²

1986

J Bacteriol

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The expression of the blaP gene for the ,B-lactamase of Bacillus licheniformis was examined by transcriptional analyses. Radiolabeled probes containing the blaP gene or various regions 3' or 5' to it were used to analyze RNA samples prepared from induced and uninduced cultures of wild-type and mutant B. licheniformis strains.The level of blaP mRNA was low in uninduced wild-type cells. At 37°C, blaP mRNA levels reached a maximum 1 h after induction while rising up to 180-fold and then declined, but remained severalfold above the uninduced level for seyetal hours. The rate of P-lactamase synthesis was roughly proportional to the levels of blaP mRNA in both wild-type and mutant strains, indicating that regulation of (-lactamase formation occurs primarily at the level of transcription. Turnover of blaP mRNA in the presence of rifampin was rapid, giving a blaP mRNA half-life of about 2 min. Yet, high levels of blaP mRNA were maintained for at least 1 h after removal of free inducer. Three blaP mRNAs of 1.2, 2.9, and 3.4 kilobases were produced from the blaP promoter. The most abundant made up about 97% of all blaP transcripts and was also the smnallest, ending at a transcriptional terminator located about 60 bases 3' to the blaP structural gene. Variables such as incubation temperature, cytotoxicity of inducer, and type of strain had essentially no effect on the ratio of large blaP mRNA to total blaP mRNA. The 2.9-and 3.4-kilobase blaP mRNAs identify potential locations of genetically linked regulators of ,l-lactamase synthesis.P-Lactamases can be classified into three groups on the basis of enzyme structure (3,19 (14). To emphasize the evolutionary relationship among class A enzymes and to establish a uniformity in nomenclature, we refer here to the Bacillus licheniformis P-lactamase gene as blaP rather than penP as previously denoted.The blaP gene has been cloned on a 4.2-kilobase (kb) EcoRI DNA fragment (8,15,17) and sequenced (23,33). By complementation analysis of mero-and heteropolyploid strains constructed in B. licheniformis, it was shown that the 4.2-kb EcoRI DNA fragment also contains blaI, the gene encoding the repressor of blaP (17). Dubnau and Pollock (12) had shown by chromosomal DNA transformation that blaI was 90% linked to blaP, and a preliminary linkage map developed by Sherratt and Collins placed blaI 3' to blaP (40). These authors (40) also reported a second regulatory locus (Ri) 50% linked to blaP and a third unlinked locus (R2).Since multiple genetic determinants apparently control the formation of P-lactamase, it is not surprising that induction is complex. Upon induction, production of B. licheniformis ,-lactamase occurs unusually slowly, the rate increasing for * Corresponding author.

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“…It is not too clear from the literature whether true protoplasts of B. cereus have the capacity to produce inducible penicillinase. On the one hand, Sheinin (23) reported that protoplasts of B. cereus 569 could be directly induced to form penicillinase at a rate comparable to that of whole cells, whereas Duerksen (7) was not able to demonstrate induced formation of penicillinase in protoplasts of the same organism unless the cells used to produce these protoplasts had been preinduced. In an attempt to resolve this discrepancy, Wainwright and Martin (25), using spheroplasts of this organism, obtained complex results.…”

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confidence: 99%

Formation and Secretion of Induced Penicillinase in Protoplasts of Staphylococcus aureus

Coles

Gross

1973

Antimicrob Agents Chemother

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Conditions suitable for induced formation and secretion of penicillinase (EC 3.5.2.6) in protoplasts of Staphylococcus aureus were determined. No requirement was found for cells to be exposed to inducer prior to formation of protoplasts. Neither cell wall components nor mesosomes appeared to be necessary for induction or secretion. In medium containing 1.1 M sucrose about half of the formed enzyme was soluble, whereas in medium containing 0.37 M sodium succinate only about 10% of the penicillinase remained protoplast-bound. Low concentrations of polyanions (dextran sulfate and potassium polyvinyl-sulfonate) inhibited the formation of induced penicillinase, as did 4-acetamido-4'-isothiocyano-stilbene 2,2'-disulfonic acid. None of these compounds inhibited the activity of native penicillinase, and none would be expected to pass through the protoplast membrane. Penicillinase, denatured in 4 M urea, could be renatured by dilution in the presence of benzylpenicillin, and the above three inhibitors interfered strongly with this process. The results are taken as evidence that penicillinase may be secreted through the protoplast membrane in an incompletely folded form.In previous studies of the synthesis and liberation of penicillinase (EC 3.5.2.6) by cells of Staphylococcus aureus (3, 4), we showed that there is a fraction of cell-bound penicillinase, comprising up to 40% of the total, which can be liberated by incubation of the cells for short periods at 37 C in 0.15 M sodium citrate. This fraction of cell-bound exopenicillinase is replenished only under conditions permitting de novo penicillinase synthesis and is the most recently synthesized enzyme (5). No transformation of old remaining cell-bound penicillinase to exopenicillinase takes place. The bacterial cell wall has been implicated in the formation of active exoenzymes by several authors. Spheroplasts of Streptococcus faecalis were unable to produce extracellular proteinase until some cell wall component had first been resynthesized (9), and protoplasts of Bacillus subtilis failed to synthesize extracellular amylase and protease under conditions permitting the unimpaired incorporation of "4C-valine into a trichloroacetic acid-insoluble product (14).Induced enzyme synthesis in protoplasts of bacteria has been shown only in very few cases. It is not too clear from the literature whether true protoplasts of B. cereus have the capacity to produce inducible penicillinase. On the one hand, Sheinin (23) reported that protoplasts of B. cereus 569 could be directly induced to form penicillinase at a rate comparable to that of whole cells, whereas Duerksen (7) was not able to demonstrate induced formation of penicillinase in protoplasts of the same organism unless the cells used to produce these protoplasts had been preinduced. In an attempt to resolve this discrepancy, Wainwright and Martin (25), using spheroplasts of this organism, obtained complex results. The interpretation was further complicated by a high and variable rate of basal synthesis of penicillinase by no...

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Localization of the site of fixation of the inducer, penicillin, in Bacillus cereus

Cited by 16 publications

References 30 publications

Penicillin-Resistant Mechanisms in Pseudomonas aeruginosa : Binding of Penicillin to Pseudomonas aeruginosa KM 338

Penicillin-Resistant Mechanisms in Pseudomonas aeruginosa : Binding of Penicillin to Pseudomonas aeruginosa KM 338

Transcriptional analysis of beta-lactamase regulation in Bacillus licheniformis

Formation and Secretion of Induced Penicillinase in Protoplasts of Staphylococcus aureus

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