کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10835194 | 1066055 | 2005 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Nitrosative stress results in irreversible inhibition of purified mitochondrial complexes I and III without modification of cofactors
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کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Nitrosative stress results in irreversible inhibition of purified mitochondrial complexes I and III without modification of cofactors Nitrosative stress results in irreversible inhibition of purified mitochondrial complexes I and III without modification of cofactors](/preview/png/10835194.png)
چکیده انگلیسی
The effects of both nitric oxide (NO) and peroxynitrite on complexes I (NADH dehydrogenase) and III (cytochrome c reductase) isolated from bovine heart have been examined. EPR signals (“g = 2.01”) previously detected in association with loss of complex I and III activities in cultured cells and isolated mitochondria subjected to nitrosative stress are shown not to arise from these particular enzymes. Neither NO nor peroxynitrite (ONO2â) reacts to any appreciable extent with the oxidized forms of flavin mononucleotide, iron-sulfur clusters, or heme moieties found in complexes I and III. However, ONO2â is readily able to abstract electrons from the reduced forms of both complexes I and III, without any apparent modification of the enzyme cofactors. While no attempt was made in the present study to catalog all the possible modifications, it is clear that ONO2â can react with the protein moieties of the enzymes. For example, when added in excess, ONO2â derivatizes a select few tyrosine residues in both complexes I and III forming 3-nitrotyrosine as detected by immunoblots. In the case of complex I, we find a minimum of 3 out of the 46 subunits present were modified (49, â¼18, and â¼15 kDa); whereas in complex III, 4 out of the 13 subunits stained for 3-nitrotyrosine (46, 27, 7, and 6 kDa). Significant irreversible inhibition of activity required the addition of >102-fold excesses of ONO2â to the enzymes. At 103-fold excess of added ONO2â, the activity of complex I was only diminished by â¼18%, while a 60% loss of activity was observed for complex III.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Nitric Oxide - Volume 13, Issue 4, December 2005, Pages 254-263
Journal: Nitric Oxide - Volume 13, Issue 4, December 2005, Pages 254-263
نویسندگان
Linda L. Pearce, Anthony J. Kanai, Michael W. Epperly, Jim Peterson,