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ARS Home » Plains Area » Grand Forks, North Dakota » Grand Forks Human Nutrition Research Center » Dietary Prevention of Obesity-related Disease Research » Research » Publications at this Location » Publication #156584
Title: THE SPECIFIC ACTIVITY OF METHIONINE SULFOXIDE REDUCTASE IN MICE IS SIGNIFICANTLY AFFECTED BY DIETARY SELENIUM BUT NOT ZINC

Author
item Uthus, Eric
item MOSKOVITZ, JACKOB - NAT INST OF HEALTH

Submitted to: Journal of Federation of American Societies for Experimental Biology
Publication Type: Abstract Only
Publication Acceptance Date: 12/1/2003
Publication Date: 3/24/2004
Citation: Uthus, E.O., Moskovitz, J. 2004. The specific activity of methionine sulfoxide reductase in mice is significantly affected by dietary selenium but not zinc [abstract]. The Federation of American Societies for Experimental Biology Journal. 18:A916.

Interpretive Summary:

Technical Abstract: ROS-mediated oxidation of methionine (Met) residues in protein results in a racemic mixture of R and S forms of Met sulfoxide (MetO). MetO is reduced back to Met by the methionine sulfoxide reductases MsrA and MsrB. MsrA exhibits high specificity toward the S form and MsrB exhibits high specificity toward the R form of MetO. MsrB (also known as SelR) is a selenoprotein reported to contain zinc. To determine the effects of dietary selenium (Se) and zinc (Zn) on Msr activity, CD-1 mice (N=16/group) were fed, in a 2x2 design, diets containing 0 or 0.2 µg Se (as selenite)/g and 3 or 15 µg Zn/g. As an oxidative stress, half of the mice received buthionine sulfoximine (BSO; i.p.; 2 mmol/kg, 3 times/wk for the last 3 wk); the others received saline. After 9.5 wk Msr (the combined specific activities of MsrA and MsrB) was measured in brain, kidney, and liver. Se deficiency decreased (p<0.0001) Msr in all 3 tissues but Zn had no direct effect. In brain, however, Se supplementation to mice fed marginal Zn increased Msr to a greater extent than in mice fed adequate Zn (p<0.002). Surprisingly, BSO treatment slightly, but significantly decreased (p<0.002) kidney Msr. However, as related to Se status, BSO treatment had no effect on tissue Msr. The results show that Se status affects Msr (most likely through effects on the selenoprotein MsrB), marginal Zn deficiency has little effect on Msr, and the oxidative effects of BSO did not upregulate Msr activity.