Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins
The structural and functional consequences of engineering a positively charged Lys residue and replacing the natural heme with a heme-L-His derivative in the active site of sperm whale myoglobin (Mb) have been investigated. The main structural change caused by the distal T67K mutation appears to be...
Published in: | JBIC Journal of Biological Inorganic Chemistry |
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Online Access: | http://hdl.handle.net/11571/138434 https://doi.org/10.1007/s00775-004-0606-4 |
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ftunivpavia:oai:iris.unipv.it:11571/138434 2024-02-27T08:45:42+00:00 Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins RONCONE, RAFFAELLA MONZANI, ENRICO Labò S. Sanangelantoni A. M. CASELLA, LUIGI Roncone, Raffaella Monzani, Enrico Labò, S. Sanangelantoni, A. M. Casella, Luigi 2005 STAMPA http://hdl.handle.net/11571/138434 https://doi.org/10.1007/s00775-004-0606-4 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000226502300003 volume:10 firstpage:11 lastpage:24 numberofpages:14 journal:JBIC http://hdl.handle.net/11571/138434 doi:10.1007/s00775-004-0606-4 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-12944322234 MYOGLOBIN PROTEIN UNFOLDING PROTEIN DEGRADATION info:eu-repo/semantics/article 2005 ftunivpavia https://doi.org/10.1007/s00775-004-0606-4 2024-01-31T17:36:26Z The structural and functional consequences of engineering a positively charged Lys residue and replacing the natural heme with a heme-L-His derivative in the active site of sperm whale myoglobin (Mb) have been investigated. The main structural change caused by the distal T67K mutation appears to be mobilization of the propionate-7 group. Reconstitution of wild-type and T67K Mb with heme-L-His relaxes the protein fragment around the heme because it involves the loss of the interaction of one of the propionate groups which stabilize heme binding to the protein. This modification increases the accessibility of exogenous ligands or substrates to the active site. The catalytic activity of the reconstituted proteins in peroxidase-type reactions is thus significantly increased, particularly with T67K Mb. The T67K mutation slightly reduces the thermodynamic stability and the chemical stability of Mb during catalysis, but somewhat more marked effects are observed by cofactor reconstitution. Hydrogen peroxide, in fact, induces pseudo-peroxidase activity but also promotes oxidative damage of the protein. The mechanism of protein degradation involves two pathways, which depend on the evolution of radical species generated on protein residues by the Mb active species and on the reactivity of phenoxy radicals produced during turnover. Both protein oligomers and heme-protein cross-links have been detected upon inactivation. Article in Journal/Newspaper Sperm whale IRIS UNIPV (Università degli studi di Pavia) JBIC Journal of Biological Inorganic Chemistry 10 1 11 24 |
institution |
Open Polar |
collection |
IRIS UNIPV (Università degli studi di Pavia) |
op_collection_id |
ftunivpavia |
language |
English |
topic |
MYOGLOBIN PROTEIN UNFOLDING PROTEIN DEGRADATION |
spellingShingle |
MYOGLOBIN PROTEIN UNFOLDING PROTEIN DEGRADATION RONCONE, RAFFAELLA MONZANI, ENRICO Labò S. Sanangelantoni A. M. CASELLA, LUIGI Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins |
topic_facet |
MYOGLOBIN PROTEIN UNFOLDING PROTEIN DEGRADATION |
description |
The structural and functional consequences of engineering a positively charged Lys residue and replacing the natural heme with a heme-L-His derivative in the active site of sperm whale myoglobin (Mb) have been investigated. The main structural change caused by the distal T67K mutation appears to be mobilization of the propionate-7 group. Reconstitution of wild-type and T67K Mb with heme-L-His relaxes the protein fragment around the heme because it involves the loss of the interaction of one of the propionate groups which stabilize heme binding to the protein. This modification increases the accessibility of exogenous ligands or substrates to the active site. The catalytic activity of the reconstituted proteins in peroxidase-type reactions is thus significantly increased, particularly with T67K Mb. The T67K mutation slightly reduces the thermodynamic stability and the chemical stability of Mb during catalysis, but somewhat more marked effects are observed by cofactor reconstitution. Hydrogen peroxide, in fact, induces pseudo-peroxidase activity but also promotes oxidative damage of the protein. The mechanism of protein degradation involves two pathways, which depend on the evolution of radical species generated on protein residues by the Mb active species and on the reactivity of phenoxy radicals produced during turnover. Both protein oligomers and heme-protein cross-links have been detected upon inactivation. |
author2 |
Roncone, Raffaella Monzani, Enrico Labò, S. Sanangelantoni, A. M. Casella, Luigi |
format |
Article in Journal/Newspaper |
author |
RONCONE, RAFFAELLA MONZANI, ENRICO Labò S. Sanangelantoni A. M. CASELLA, LUIGI |
author_facet |
RONCONE, RAFFAELLA MONZANI, ENRICO Labò S. Sanangelantoni A. M. CASELLA, LUIGI |
author_sort |
RONCONE, RAFFAELLA |
title |
Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins |
title_short |
Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins |
title_full |
Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins |
title_fullStr |
Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins |
title_full_unstemmed |
Catalytic Activity, Stability, Unfolding, and Degradation Pathways of Engineered and Reconstituted Myoglobins |
title_sort |
catalytic activity, stability, unfolding, and degradation pathways of engineered and reconstituted myoglobins |
publishDate |
2005 |
url |
http://hdl.handle.net/11571/138434 https://doi.org/10.1007/s00775-004-0606-4 |
genre |
Sperm whale |
genre_facet |
Sperm whale |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000226502300003 volume:10 firstpage:11 lastpage:24 numberofpages:14 journal:JBIC http://hdl.handle.net/11571/138434 doi:10.1007/s00775-004-0606-4 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-12944322234 |
op_doi |
https://doi.org/10.1007/s00775-004-0606-4 |
container_title |
JBIC Journal of Biological Inorganic Chemistry |
container_volume |
10 |
container_issue |
1 |
container_start_page |
11 |
op_container_end_page |
24 |
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1792054988866846720 |