The Inactivation of Microbial Enzymes in Vivo

Switzer, Robert L.

doi:10.1146/annurev.mi.31.100177.001031

Cited by 101 publications

(40 citation statements)

References 42 publications

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“…This type of inactivation may be more common than is generally recognized (21). Koischwitz and Kleinkauf (13) found that, during the purification of gramicidin S synthetase of Bacillus brevis, the enzyme was markedly sensitive to inactivation by extracellular proteases.…”

Section: Resultsmentioning

confidence: 96%

“…All three were growth inhibited, but Streptococcus sanguis did not lyse or show loss of viability, Streptococcus pyogenes exhibited loss of viability but did not lyse, and Streptococcus pneumoniae showed both loss of viability and autolysis. The authors point out that, of the three species, active cell wall-associated autolysins have been demonstrated only for the pneumococcus (8,21). However, Ranhand (16) observed that competent Streptococcus sanguis cells autolyzed when suspended in buffer at pH 9.0.…”

Section: Resultsmentioning

confidence: 99%

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Extracellular proteases increase tolerance of Bacillus subtilis to nafcillin

Jolliffe¹,

Doyle²,

Streips³

1982

Antimicrob Agents Chemother

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Mutants of Bacillus subtilis capable of secreting high amounts of protease were highly tolerant to the lethal and lytic effects of nafcillin. Protease-deficient mutants were more susceptible. However, when subtilisin was added exogenously to a protease-deficient strain, the organism assumed the characteristics of nafcillin tolerance. Similarly, when phenylmethylsulfonyl fluoride, a serine protease inhibitor, was added to the tolerant strains, they became susceptible to nafcillin-induced lysis. The effects of nafcillin on B. subtilis were studied with both viability determinations and assay of cellular lysis. The minimum inhibitory concentrations of nafcillin tended to be higher for the protease hyperproducing strains, but these values could be reduced by the protease inhibitor. No loss of antibiotic activity was observed when nafcillin was incubated with either subtilisin or trypsin. Furthermore, protease and autolysin from B. subtilis were not modified by nafcillin. The results showed that extracellular proteases could render B. subtilis relatively tolerant to the killing and lytic effects of a cell wall antibiotic. The proteases were probably acting on the autolysins of the organism, thereby increasing tolerance to nafcillin.Autolytic enzymes have been implicated in several growth and division events in bacteria. Formation of a septum and subsequent cell separation appear to depend on a functional autolysin (6,18). Additional manifestations of autolytic activity in bacterial cells may be the ability to take up exogenous DNA (transformation) (16) and the turnover of cell wall components. Moreover, lysis in energy-depletedBacillus subtilis is a result of poorly regulated autolytic activity (10).In several different kinds of microorganisms, autolysin activity appears to be necessary for the killing and lytic effects induced by cell wall antibiotics such as penicillin (7,11,14). Other workers suggest that the susceptibility of bacteria to penicillin is unrelated to the level of autolysin (3). To clearly distinguish among penicillin-induced ceL killing, cellular lysis, cell wall turnover, and autolysin levels, a system is required in which the various parameters can be monitored and modified. We found that the addition of proteases and protease inhibitors had a marked effect on the rate of turnover of peptidoglycan in B. subtilis (9). Turnover is an expression of autolytic activity but does not necessarily reflect absolute levels of autolysins t Present address:

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Section: Resultsmentioning

confidence: 96%

Section: Resultsmentioning

confidence: 99%

Extracellular proteases increase tolerance of Bacillus subtilis to nafcillin

Jolliffe¹,

Doyle²,

Streips³

1982

Antimicrob Agents Chemother

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“…The rate constants of synthesis were calculated as described in the text. One unit, U, of activity is defined as the amount of enzyme that hydrolyzes 1 Calculated from the decrease of radioactivity in fructose bisCalculated from changes in specific activity after a shift from phosphatase along lime.…”

Section: In Dgferent Conditionsmentioning

confidence: 99%

Turnover of Yeast Fructose-Bisphosphatase in Different Metabolic Conditions

1980

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Earlier work demonstrated that addition of glucose to yeast growing on noncarbohydrate carbon sources sharply reduces the levels of fructose bisphosphatase. This report indicates that the decrease in the levels of fructose bisphosphatase is accompanied by a parallel decrease of cross‐reacting material to specific antibody to fructose bisphosphatase. Use of the specific antibody shows that the loss of activity is irreversible and that its reappearance requires synthesis of protein de novo. The protein is highly stable during growth in ethanol (half life about 90 h). Addition of glucose increases the rate of degradation about 200‐fold. It is shown that the values of the rates of synthesis and degradation of fructose bisphosphatase vary with the metabolic situation of the yeast.

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“…The p-amylases from both mutants were remarkably inactivated only in the presence of the proteinase, as reported for other microbial enzymes. 6 ) This decrease in p-amylase activities also was parallel with the increase in TCA-soluble nitrogenous compounds in the incubation mixtures. These results agreed with the assumption that p-amylase of BQIO-S1 Spo I might be inactivated by the co-existing proteinase, but could not explain the higher stability of p-amylase in the culture broth of BQIO-SI Spo II.…”

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confidence: 83%