Folding of apominimyoglobin.
The acid unfolding pathway of apominimyoglobin (apo-mini-Mb), a 108-aa fragment (aa 32-139) of horse heart apomyoglobin has been studied by means of circular dichroism, in comparison with the native apoprotein. Similar to sperm whale apomyoglobin [Hughson, F. M., Wright, P. E. & Baldwin, R. L. (...
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ftpubmed:oai:pubmedcentral.nih.gov:45260 2023-05-15T18:26:48+02:00 Folding of apominimyoglobin. De Sanctis, G Ascoli, F Brunori, M 1994-11-22 http://www.ncbi.nlm.nih.gov/pmc/articles/PMC45260 http://www.ncbi.nlm.nih.gov/pubmed/7972092 en eng http://www.ncbi.nlm.nih.gov/pmc/articles/PMC45260 http://www.ncbi.nlm.nih.gov/pubmed/7972092 Research Article Text 1994 ftpubmed 2013-08-29T08:03:00Z The acid unfolding pathway of apominimyoglobin (apo-mini-Mb), a 108-aa fragment (aa 32-139) of horse heart apomyoglobin has been studied by means of circular dichroism, in comparison with the native apoprotein. Similar to sperm whale apomyoglobin [Hughson, F. M., Wright, P. E. & Baldwin, R. L. (1990) Science 249, 1544-1548], a partly folded intermediate (alpha-helical content approximately 35%) is populated at pH 4.2 for horse heart apomyoglobin. For this intermediate, Hughson et al. proposed a structural model with a compact subdomain involving tertiary interactions between the folded A, G, and H helices, with the remainder of the protein essentially unfolded. As described in this paper, a folding intermediate with an alpha-helical content of approximately 33% is populated at pH 4.3-5.0 also in apo-mini-Mb. The acid unfolding pathway is similarly affected in both the native and the mini apoprotein by 15% trifluoroethanol, a helix-stabilizing compound. Thus, the folding of the apo-mini-Mb intermediate is similar to that observed for the native apoprotein, in spite of the absence in the miniprotein of the A helix and of a large part of the H helix, which are crucial for the stability of apo-Mb intermediate. Our results suggest that acquisition of a folded state in apo-mini-Mb occurs through an alternative pathway, which may or may not be shared also by apo-Mb. Text Sperm whale PubMed Central (PMC) Baldwin ENVELOPE(163.300,163.300,-72.250,-72.250) |
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Research Article De Sanctis, G Ascoli, F Brunori, M Folding of apominimyoglobin. |
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Research Article |
description |
The acid unfolding pathway of apominimyoglobin (apo-mini-Mb), a 108-aa fragment (aa 32-139) of horse heart apomyoglobin has been studied by means of circular dichroism, in comparison with the native apoprotein. Similar to sperm whale apomyoglobin [Hughson, F. M., Wright, P. E. & Baldwin, R. L. (1990) Science 249, 1544-1548], a partly folded intermediate (alpha-helical content approximately 35%) is populated at pH 4.2 for horse heart apomyoglobin. For this intermediate, Hughson et al. proposed a structural model with a compact subdomain involving tertiary interactions between the folded A, G, and H helices, with the remainder of the protein essentially unfolded. As described in this paper, a folding intermediate with an alpha-helical content of approximately 33% is populated at pH 4.3-5.0 also in apo-mini-Mb. The acid unfolding pathway is similarly affected in both the native and the mini apoprotein by 15% trifluoroethanol, a helix-stabilizing compound. Thus, the folding of the apo-mini-Mb intermediate is similar to that observed for the native apoprotein, in spite of the absence in the miniprotein of the A helix and of a large part of the H helix, which are crucial for the stability of apo-Mb intermediate. Our results suggest that acquisition of a folded state in apo-mini-Mb occurs through an alternative pathway, which may or may not be shared also by apo-Mb. |
format |
Text |
author |
De Sanctis, G Ascoli, F Brunori, M |
author_facet |
De Sanctis, G Ascoli, F Brunori, M |
author_sort |
De Sanctis, G |
title |
Folding of apominimyoglobin. |
title_short |
Folding of apominimyoglobin. |
title_full |
Folding of apominimyoglobin. |
title_fullStr |
Folding of apominimyoglobin. |
title_full_unstemmed |
Folding of apominimyoglobin. |
title_sort |
folding of apominimyoglobin. |
publishDate |
1994 |
url |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC45260 http://www.ncbi.nlm.nih.gov/pubmed/7972092 |
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ENVELOPE(163.300,163.300,-72.250,-72.250) |
geographic |
Baldwin |
geographic_facet |
Baldwin |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_relation |
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC45260 http://www.ncbi.nlm.nih.gov/pubmed/7972092 |
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1766208775456292864 |