1. Role of redox environment on the oligomerization of higher molecular weight adiponectin
- Author
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David B. Briggs, Tsu Shuen Tsao, Pamela R. Malinowski, Martha Nunez, and Rebecca M. Giron
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lcsh:Animal biochemistry ,Oxidative phosphorylation ,Oligomer ,Redox ,Biochemistry ,Dithiothreitol ,Polymerization ,lcsh:Biochemistry ,chemistry.chemical_compound ,Oxidizing agent ,Animals ,lcsh:QD415-436 ,Disulfides ,lcsh:QP501-801 ,Molecular Biology ,Mercaptoethanol ,Adiponectin ,Protein Stability ,Endoplasmic reticulum ,nutritional and metabolic diseases ,Molecular Weight ,chemistry ,Cattle ,Oxidation-Reduction ,hormones, hormone substitutes, and hormone antagonists ,Research Article - Abstract
Background Adiponectin is an adipocyte-secreted hormone with insulin-sensitizing and anti-inflammatory actions. The assembly of trimeric, hexameric, and higher molecular weight (HMW) species of adiponectin is a topic of significant interest because physiological actions of adiponectin are oligomer-specific. In addition, adiponectin assembly is an example of oxidative oligomerization of multi-subunit protein complexes in endoplasmic reticulum (ER). Results We previously reported that trimers assemble into HMW adiponectin via intermediates stabilized by disulfide bonds, and complete oxidation of available cysteines locks adiponectin in hexameric conformation. In this study, we examined the effects of redox environment on the rate of oligomer formation and the distribution of oligomers. Reassembly of adiponectin under oxidizing conditions accelerated disulfide bonding but favored formation of hexamers over the HMW species. Increased ratios of HMW to hexameric adiponectin could be achieved rapidly under oxidizing conditions by promoting disulfide rearrangement. Conclusions Based upon these observations, we propose oxidative assembly of multi-subunit adiponectin complexes in a defined and stable redox environment is favored under oxidizing conditions coupled with high rates of disulfide rearrangement.
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