<b>THE EFFECTS OF EXOGENOUS CATALASE ON BROAD‐SPECTRUM NEAR‐UV (300‐400 nm) TREATED</b><i>Escherichia coli</i> CELLS

Sammartano, Lauri J.; Tuveson, R. W.

doi:10.1111/j.1751-1097.1984.tb05348.x

Cited by 41 publications

(25 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…H202 has been reported to be an important photoproduct in NUV toxicity (7,(38)(39)(40)46). Our data, however, show that H202 itself does not mediate the toxic effects of broadband NUV at a low fluence rate, on cells.…”

Section: Discussioncontrasting

confidence: 51%

See 1 more Smart Citation

Oxidative mechanisms of toxicity of low-intensity near-UV light in Salmonella typhimurium

Kramer¹,

Ames²

1987

J Bacteriol

View full text Add to dashboard Cite

The exposure of Salmonella typhimurium to environmentally relevant near-UV light stress has been studied by the use of a low-intensity, broad-band light source. The exposure of cells to such a light source rapidly induced a growth delay; after continuous exposure for 3 to 4 h, cells began to die at a rapid rate. The oxidative defense regulon controlled by the oxyR gene was involved in protecting cells from being killed by near-UV light. This killing may be potentiated by the overexpression of near-UV-absorbing proteins. These results are consistent with near-UV toxicity involving the absorption of light by endogenous photosensitizers, leading to the production of active oxygen species. We have shown, however, that one such species, H2O2, is not a major photoproduct involved in killing by near-UV light. Strains lacking alkyl hydroperoxide reductase were more sensitive to near-UV light, indicating that such hydroperoxides may be photoproducts. Near-UV exposure induced sensitivity to high salt levels, indicating that membranes may be a target of near-UV toxicity and a possible source of alkyl hydroperoxides. The demonstration of the inactivation of the heme-containing protein catalase indicates that direct destruction of UV-absorbing macromolecules could be another factor in near-UV toxicity. Cells which have been exposed to near-UV light for long, but sublethal, periods of time (up to 4 h) can recover and resume growth if the UV exposure is stopped but become progressively more sensitive to further stresses, such as H2O2. This result indicates that cells gradually accumulated damage during near-UV exposure until toxic levels were reached.

show abstract

Section: Discussioncontrasting

confidence: 51%

“…Evidence has been presented which indicates that one such * Corresponding author. activated oxygen species, H202, is formed by NUV exposure (38,39,46). Catalase added to the medium was shown to protect against killing by NUV (38), and pretreatment with low doses of H202 was shown to induce resistance to killing by NUV (39).…”

mentioning

confidence: 99%

Oxidative mechanisms of toxicity of low-intensity near-UV light in Salmonella typhimurium

Kramer¹,

Ames²

1987

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…The role of catalase in preventing damage mediated by visible light or near-UV has not been investigated by itself in N. crassa. H202 has been strongly implicated in near-UV damage to bacterial cells, however, and a protective role for catalase has been observed (28,29). Interestingly, reduced conidial longevity in N. crassa has been correlated with deficiencies in the activities of catalase and other antioxygenic enzymnes (24).…”

Section: Discussionmentioning

confidence: 99%

Evidence for three differentially regulated catalase genes in Neurospora crassa: effects of oxidative stress, heat shock, and development

Chary

Natvig

1989

J Bacteriol

View full text Add to dashboard Cite

Genetic and biochemical studies demonstrated that Neurospora crassa possesses three catalases encoded by three separate structural genes. The specific activities of the three enzymes varied in response to superoxidemediated stress, heat shock, and development. The three loci, which we designated cat-i, cat-2, and cat-3, map to the right arms of chromosomes III, VII, and III, respectively. The cat-i-encoded enzyme (designated Cat-i; estimated molecular weight, 315,000; pI 5.2) was the predominant catalase in rapid-growth mycelium, and its activity was substantially increased in paraquat-treated and heat-shocked mycelium. Cat-2 (Mw, 165,000; p1 5.4) was absent from rapid-growth mycelium but present at low levels in conidia and stationary-phase mycelium. It was the predominant catalase in extracts derived from mycelium that had been heat shocked for 2 h. Cat-3 (Mw, 340,000; pl 5.5) was the predominant catalase in extracts from mature conidia.

show abstract

“…(Fridovich, 1978), the same intermediates thought to mediate the oxygen dependent toxicity of i on i z i ng rad i at i on (Moody and Hassan, 1982 Gutteridge, 1985), y-rays (Van Hernnen and Meul ing, 1975), x-râys (Sanrnartano and Tuveson, 1984), near-UV I ight (Sanmartano and Tuveson, 1984), radiomimetic drugs (Breimer and Lindahl, f985), and certain enzymes (Halliwell and Gutteridge,l9B5) can directly contribute to or augment the production of toxic oxygen spec i es.…”

Section: List Of Figures Pagementioning

confidence: 99%

“…These dinucleotides have been termed alarrÐnes (Stephens et al, 1975) (Teo et al,1986). t{organ et al, (19s6) Three factor cotransductional crosses rnapped RatE at 37.8 min in the order pps-pheS-pfk9-RatE-xthÅ (Loewen, 1984) and RatF at 59 min in the order srl-mttS-RatF-iap-cysll-pyrG (Loewen and Triggs, 1984) Tuveson, 1984). E, coli twtants hypersensitive to NUv were isolated (Tuveson, l98l) and later iclentif ied as RatF (Hp I t) mutants (Sanrnartano et at,, 1986 (Tuveson and Sanrnartano, 1986).…”

Section: List Of Figures Pagementioning

confidence: 99%

Physical characterization of katG, encoding catalase HPI of Escherichia coli

Triggs-Raine

Loewen

1987

Gene

View full text Add to dashboard Cite

THE EFFECTS OF EXOGENOUS CATALASE ON BROAD‐SPECTRUM NEAR‐UV (300‐400 nm) TREATEDEscherichia coli CELLS

Cited by 41 publications

References 29 publications

Oxidative mechanisms of toxicity of low-intensity near-UV light in Salmonella typhimurium

Oxidative mechanisms of toxicity of low-intensity near-UV light in Salmonella typhimurium

Evidence for three differentially regulated catalase genes in Neurospora crassa: effects of oxidative stress, heat shock, and development

Physical characterization of katG, encoding catalase HPI of Escherichia coli

Contact Info

Product

Resources

About