کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1987307 1540287 2011 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Molecular masses and sedimentation coefficients of extracellular hemoglobin of Glossoscolex paulistus: Alkaline oligomeric dissociation
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Molecular masses and sedimentation coefficients of extracellular hemoglobin of Glossoscolex paulistus: Alkaline oligomeric dissociation
چکیده انگلیسی

The giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) has a molecular mass (M) of 3600 ± 100 kDa and a standard sedimentation coefficient (s20,w0) of 58 S, estimated by analytical ultracentrifugation (AUC). In the present work, further AUC studies were developed for HbGp, at pH 10.0, which favors oligomeric dissociation into lower M species. The HbGp oligomer is formed by globin chains a, b, c and d plus the linker chains. The pure monomeric fraction, subunit d, and HbGp at pH 10.0, in the presence of β-mercaptoethanol, were also studied. Our results indicate that for samples of pure subunit d  , besides the monomeric species with s20,w0 of 2.0 S, formation of dimer of subunit d   is observed with s20,w0 of around 2.9 S. For the whole HbGp at pH 10.0 contributions from monomers, trimers and linkers are observed. No contribution from 58 S species was observed for the sample of oxy-HbGp at pH 10.0, showing its complete dissociation. For cyanomet-HbGp form a contribution of 17% is observed for the un-dissociated oligomer, consistent with data from other techniques that show the cyanomet-form is more stable as compared to oxy-HbGp. Masses of HbGp subunits, especially trimer abc and monomeric chains a, b, c and d, were also estimated from sedimentation equilibrium data, and are in agreement with the results from MALDI-TOF-MS.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Biological Macromolecules - Volume 48, Issue 1, 1 January 2011, Pages 183–193
نویسندگان
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