Effects of carotenoids from Deinococcus radiodurans on protein oxidation.
OBJECTIVE
To evaluate the antioxidant effect of carotenoids from Deinococcus radiodurans on protein.


RESULTS
Deinococcus radiodurans strain R1 (ATCC 13939) and its mutant strain R1DeltacrtB were used for this study. The total carotenoids (R1ex) from D. radiodurans were obtained by extraction with acetone/methanol (7 : 2, by vol), and their antioxidant activity was measured using the DPPH (2,2-diphenyl-1-picrylhydrazyl) system. The protein oxidation level, in vitro and in the cell, was measured using the DNPH (2,4-dinitrophenyl hydrazine) method. The carotenoid extract R1ex scavenged 40.2% DPPH radicals compared to beta-carotene (31.7%) at a concentration of 0.5 mg ml(-1). The intracellular level of protein oxidation in mutant R1DeltacrtB, which does not contain carotenoid, was 0.0212 mmol mg(-1) protein which is significantly greater than that in the wild type (0.0169 mmol mg(-1) protein) following the treatment with H(2)O(2). The purified major carotenoid product (deinoxanthin) from the wild type showed a greater inhibition of oxidative damage in bovine serum albumin than lycopene or lutein.


CONCLUSIONS
Carotenoids prevent protein oxidation and contribute to the resistance to cell damage in D. radiodurans.


CONCLUSIONS
Our results provide the evidence that carotenoids can protect proteins in D. radiodurans against oxidative stress.
Institute of Nuclear-Agricultural Sciences, Zhejiang University, Hangzhou, China.
B
B
Tian
Z
Z
Sun
S
S
Shen
H
H
Wang
J
J
Jiao
L
L
Wang
Y
Y
Hu
Y
Y
Hua
D001426:Bacterial Proteins / Q000378:metabolism; D001713:Biphenyl Compounds; D002338:Carotenoids / Q000737:chemistry*; D034301:Deinococcus / Q000737:chemistry*; D016166:Free Radical Scavengers / Q000737:chemistry*; D014975:Lutein / Q000737:chemistry; D000077276:Lycopene; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010851:Picrates; D050050:Protein Carbonylation
D001426:Bacterial Proteins; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D002338:Carotenoids; C004931:1,1-diphenyl-2-picrylhydrazyl; D000077276:Lycopene; D014975:Lutein