Tritium exchange of spectrin versus temperature

Autor:	D, Bonnet, M C, Marden, E, Begard, G H, Hoa, P, Douzou
Rok vydání:	2007
Předmět:	chemistry.chemical_classification Molecular model Globular protein Organic Chemistry Kinetics Biophysics Spectrin Thermodynamics General Medicine Tritium Biochemistry Catalysis Biomaterials Nuclear magnetic resonance chemistry Ionic strength Humans Molecule Hemochromatosis
Zdroj:	Biopolymers. 23:2587-2602
ISSN:	1097-0282 0006-3525
DOI:	10.1002/bip.360231130
Popis:	Tritium-exchange experiments were performed to assess the dynamics of the spectrin molecule. From the kinetics presented, spectrin appears as a fast-exchanging protein compared to globular proteins. This is easily explained by its known elongated structure. Spectrin tritium exchange is also shown to be highly temperature sensitive, even in buffer conditions that greatly reduce the temperature dependence of hydroxyl catalyst concentration. At high ionic strength, the exchange rates of specific hydrogens deduced from a power-law simulation are shown to exhibit an Arrhenius behavior, with enthalpies ranging from 70 to 140 kjmol−1. These results are discussed in relation to the known high α-helix content of spectrin. Finally, a molecular model of α-helix opening is proposed that provides satisfactory agreement with the totality of the spectrin behavior in tritium-exchange experiments.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::8c1bf63feba694296687dee431e11b38 https://doi.org/10.1002/bip.360231130 Zobrazit plný text záznamu Plný text