کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1910279 | 1046762 | 2010 | 10 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effects of age and calorie restriction on tryptophan nitration, protein content, and activity of succinyl-CoA:3-ketoacid CoA transferase in rat kidney mitochondria Effects of age and calorie restriction on tryptophan nitration, protein content, and activity of succinyl-CoA:3-ketoacid CoA transferase in rat kidney mitochondria](/preview/png/1910279.png)
This study examined the protein targets of nitration and the consequent impact on protein function in rat kidney mitochondria at 4, 13, 19, and 24 months of age. Succinyl-CoA transferase (SCOT), a rate-limiting enzyme in the degradation of ketone bodies, was the most intensely reactive protein against anti-3-nitrotyrosine antibody in rat kidney mitochondria. However, subsequent mass spectrometric and amino acid analyses of purified SCOT indicated that tryptophan 372, rather than a tyrosine residue, was the actual site of simultaneous additions of nitro and hydroxy groups. This finding suggests that identification of nitrated tyrosine residues based solely on reactivity with anti-3-nitrotyrosine antibody can be potentially misleading. Between 4 and 24 months of age, the amounts of SCOT protein and catalytic activity, expressed per milligram of mitochondrial proteins, decreased by 55 and 45%, respectively. SCOT, and particularly its nitrated carboxy-terminal region, was relatively more susceptible to in vitro proteolysis than other randomly selected kidney mitochondrial proteins. The age-related decreases in SCOT protein amount and catalytic activity were prevented by a relatively long-term 40% reduction in the amount of food intake. Loss of SCOT protein in the aged rats may attenuate the capacity of kidney mitochondria to utilize ketone bodies for energy production.
Journal: Free Radical Biology and Medicine - Volume 48, Issue 4, 15 February 2010, Pages 609–618