Photomodification of Biological Membranes With Emphasis on Singlet Oxygen Mechanisms

Valenzeno, Dennis Paul

doi:10.1111/j.1751-1097.1987.tb04749.x

Cited by 263 publications

(126 citation statements)

References 133 publications

Supporting

Mentioning

120

Contrasting

Unclassified

Order By: Relevance

“…Singlet oxygen and/or superoxide radical are probable candidates. It is well known that porphyrins (2,14,23) are very efficient photogenerators of these destructive agents. Surprisingly, PSII reaction center seems to be more sensitive to photodamage effects than bacterial reaction center (3), despite the presence of the same amount of carotenoid in both reaction center species.…”

Section: Resultsmentioning

confidence: 99%

Stabilization of Isolated Photosystem II Reaction Center Complex in the Dark and in the Light Using Polyethylene Glycol and an Oxygen-Scrubbing System

McTavish¹,

Picorel²,

Seibert³

1989

Plant Physiol.

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Stabilization of Isolated Photosystem II Reaction Center Complex in the Dark and in the Light Using Polyethylene Glycol and an Oxygen-Scrubbing System

McTavish¹,

Picorel²,

Seibert³

1989

Plant Physiol.

View full text Add to dashboard Cite

“…In aqueous solutions, ZnBG is expected to be mainly monomeric because of its more hydrophilic side chains. Some speculate that the aggregation of porphyrins is a major factor determining the quantum yield of singlet oxygen production and that monomeric porphyrins produce singlet oxygen in a greater yield than those aggregated (31).…”

Section: Discussionmentioning

confidence: 99%

Effect of light exposure on metalloporphyrin-treated newborn mice

et al. 2012

View full text Add to dashboard Cite

Background: Neonatal hyperbilirubinemia arises from increased bilirubin production and decreased bilirubin elimination. Although phototherapy safely and effectively reduces bilirubin levels, recent evidence shows that it has adverse effects. Therefore, alternative treatments are warranted. Metalloporphyrins, competitive inhibitors of heme oxygenase (hO), the rate-limiting enzyme in bilirubin production, effectively reduce bilirubin formation; however, many are photoreactive. here, we investigated possible photosensitizing effects of chromium mesoporphyrin (crMP) and zinc deuteroporphyrin bis-glycol (ZnBG). Methods and results: Administration of crMP or ZnBG to 3-d-old mouse pups (3.75-30.0 µmol/kg intraperitoneally) and exposure to cool white (F20T12cW) and blue (TL20W/52) fluorescent lights (+L) for 3 h, resulted in a dose-dependent mortality (50% lethal dose (LD50) = 21.5 and 19.5 µmol/kg, respectively). In contrast to ZnBG, there was no significant difference in survival between the crMP+L and crMP groups. Following 30 µmol/kg ZnBG+L, we found significant weight loss, decreased liver antioxidant capacities, and increased aspartate aminotransaminase levels. At 6-d post-light exposure, ZnBG+L-treated pups showed gross and histologic skin changes at doses >7.5 µmol/kg. No lethality was observed following treatment with 30 µmol ZnBG/kg plus exposure to blue light-emitting diodes. Phototoxicity of ZnBG was dependent on light source, emission spectrum, and irradiance. conclusion: Low doses of ZnBG (<3.75 µmol/kg) retained maximal hO inhibitory potency without photosensitizing effects, and therefore are potentially useful in treating neonatal hyperbilirubinemia.

show abstract

“…Although D. radiodurans has a reduced number of respiratory chain enzymes and proteins with iron-sulfur clusters (see "Metabolic Configuration of D. radiodurans") along with extremely efficient ROSscavenging mechanisms (see "Antioxidation Protection in D. radiodurans"), its sensitivity to singlet oxygen generated in the presence of photosensitizers may overcome its antioxidant mechanisms and thereby account for its high level of sensitivity to UV-A. Additionally, UV-A-induced singlet oxygen may target lipid components of the D. radiodurans cell wall, the unsaturated fatty acids in particular, the double bonds of which are susceptible to oxidation (68,631). Lipid peroxidation disrupts membrane integrity, which may lead to the loss of chromosome anchoring to the cell membrane (79,154) …”

Section: Sensitivity Of D Radiodurans To Uv-a Radiation and Singlet mentioning

confidence: 99%

Oxidative Stress Resistance inDeinococcus radiodurans

Slade

Radman

2011

Microbiol Mol Biol Rev

648

639

View full text Add to dashboard Cite

SUMMARY Deinococcus radiodurans is a robust bacterium best known for its capacity to repair massive DNA damage efficiently and accurately. It is extremely resistant to many DNA-damaging agents, including ionizing radiation and UV radiation (100 to 295 nm), desiccation, and mitomycin C, which induce oxidative damage not only to DNA but also to all cellular macromolecules via the production of reactive oxygen species. The extreme resilience of D. radiodurans to oxidative stress is imparted synergistically by an efficient protection of proteins against oxidative stress and an efficient DNA repair mechanism, enhanced by functional redundancies in both systems. D. radiodurans assets for the prevention of and recovery from oxidative stress are extensively reviewed here. Radiation- and desiccation-resistant bacteria such as D. radiodurans have substantially lower protein oxidation levels than do sensitive bacteria but have similar yields of DNA double-strand breaks. These findings challenge the concept of DNA as the primary target of radiation toxicity while advancing protein damage, and the protection of proteins against oxidative damage, as a new paradigm of radiation toxicity and survival. The protection of DNA repair and other proteins against oxidative damage is imparted by enzymatic and nonenzymatic antioxidant defense systems dominated by divalent manganese complexes. Given that oxidative stress caused by the accumulation of reactive oxygen species is associated with aging and cancer, a comprehensive outlook on D. radiodurans strategies of combating oxidative stress may open new avenues for antiaging and anticancer treatments. The study of the antioxidation protection in D. radiodurans is therefore of considerable potential interest for medicine and public health.

show abstract

Photomodification of Biological Membranes With Emphasis on Singlet Oxygen Mechanisms

Cited by 263 publications

References 133 publications

Stabilization of Isolated Photosystem II Reaction Center Complex in the Dark and in the Light Using Polyethylene Glycol and an Oxygen-Scrubbing System

Stabilization of Isolated Photosystem II Reaction Center Complex in the Dark and in the Light Using Polyethylene Glycol and an Oxygen-Scrubbing System

Effect of light exposure on metalloporphyrin-treated newborn mice

Oxidative Stress Resistance inDeinococcus radiodurans

Contact Info

Product

Resources

About