کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8305232 | 1538425 | 2014 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Bound cardiolipin is essential for cytochrome c oxidase proton translocation
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کلمات کلیدی
PLA2TMPDDOPCCCCPRCRCCORP-HPLC1,2-dioleoyl-sn-glycero-3-phosphocholine - 1،2-dioleoyl-sn-glycero-3-phosphocholine1,2-dioleoyl-sn-glycero-3-phosphoethanolamine - 1،2-dioleoyl-sn-glycero-3-phosphoethanolaminephospholipase A2 - آنزیم فسفولیپاز A2 cytochrome c oxidase - سیتوکروم سی اکسیدازphosphatidylcholine - فسفاتیدیل کولینphosphatidylethanolamine - فسفاتیدیلتانولامینLiposomes - لیپوزومrespiratory control ratio - نسبت کنترل تنفسیproton pumping - پروتون پمپاژDOPE - پیش بینی کردنCardiolipin - کاردیولیپینcarbonyl cyanide m-chlorophenylhydrazone - کربنیل سیانید m-chlorophenylhydrazoneReversed phase high-performance liquid chromatography - کروماتوگرافی مایع با کارایی با رزین فاز برگشت پذیر
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
زیست شیمی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Bound cardiolipin is essential for cytochrome c oxidase proton translocation Bound cardiolipin is essential for cytochrome c oxidase proton translocation](/preview/png/8305232.png)
چکیده انگلیسی
The proton pumping activity of bovine heart cytochrome c oxidase (CcO) is completely inhibited when all of the cardiolipin (CL) is removed from the enzyme to produce monomeric CcO containing only 11 subunits. Only dimeric enzyme containing all 13 subunits and 2-4 cardiolipin per CcO monomer exhibits a “normal” proton translocating stoichiometry of â¼1.0 H+ per/eâ when reconstituted into phospholipid vesicles. These fully active proteoliposomes have high respiratory control ratios (RCRÂ =Â 7-15) with 75-85% of the CcO oriented with the cytochrome c binding sites exposed to the external medium. In contrast, reconstitution of CL-free CcO results in low respiratory control ratios (RCRÂ <Â 5) with the enzyme randomly oriented in the vesicles, i.e., â¼50 percent oriented with the cytochrome c binding site exposed on the outside of the vesicle. Addition of exogenous CL to the CL-free enzyme completely restores electron transport activity, but restoration of proton pumping activity does not occur. This is true whether CL is added to CL-free CcO prior to reconstitution into phospholipid vesicles, or whether CL is included in the phospholipid mixture that is used to form the vesicles. Another consequence of CL removal is the inability of the 11-subunit, CL-free enzyme to dimerize upon exposure to either cholate or the cholate/PC/PE/CL mixture used during proteoliposome formation (monomeric, 13-subunit, CL-containing CcO completely dimerizes under these conditions). Therefore, a major difference between reconstitution of CL-free and CL-containing CcO is the incorporation of monomeric, rather than dimeric CcO into the vesicles. We conclude that bound CL is necessary for proper insertion of CcO into phospholipid vesicles and normal proton translocation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochimie - Volume 105, October 2014, Pages 159-164
Journal: Biochimie - Volume 105, October 2014, Pages 159-164
نویسندگان
Andrej Musatov, Neal C. Robinson,