Dynamic properties of some β-chain mutant hemoglobins

Thr substitution, localized in the heme pocket, which results in decreased coupling with low-frequency modes and increased anharmonic motions. Mutations involving residue beta Lys-144(Hc1) at the C-terminal and residue beta Cys-112(G14) at the alpha 1 beta 1 interface have a smaller effect consisting in an increased coupling with low-frequency modes. Mutations at the beta-N-terminal and at the alpha 1 beta 2 interface have no effect on the dynamic properties of the same heme pocket. -->

ISSN:	1097-0134 0887-3585
Přístupová URL adresa:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::41a88ec41bda1e4757f03c61ff8e962b https://doi.org/10.1002/prot.340220103
Rights:	CLOSED
Přírůstkové číslo:	edsair.doi.dedup.....41a88ec41bda1e4757f03c61ff8e962b
Autor:	Maurizio Leone, Cupane A, William S. Brinigar, Valeria Militello, A-Lien Lu, Clara Fronticelli
Rok vydání:	1995
Předmět:	Voigt profile Coupling constant Base Sequence Chemistry Protein dynamics Molecular Sequence Data Anharmonicity Hemoglobin A Heme Biochemistry Recombinant Proteins Molecular electronic transition Cold Temperature Crystallography Carboxyhemoglobin Models Chemical Spectrophotometry Structural Biology Molecular vibration Mutation Mutagenesis Site-Directed Homogeneous broadening Rotational–vibrational coupling Molecular Biology
Zdroj:	Proteins: Structure, Function, and Genetics. 22:12-19
ISSN:	1097-0134 0887-3585
Popis:	The thermal behavior of the Soret band relative to the carbonmonoxy derivatives of some beta-chain mutant hemoglobins is studied in the temperature range 300-10 K and compared to that of wild-type carbonmonoxy hemoglobin. The band profile at various temperatures is modeled as a Voigt function that accounts for homogeneous broadening and for the coupling with high- and low-frequency vibrational modes, while inhomogeneous broadening is taken into account with a gaussian distribution of purely electronic transition frequencies. The various contributions to the over-all bandwidth are singled out with this analysis and their temperature dependence, in turn, gives information on structural and dynamic properties of the system studied. In the wild-type and mutant hemoglobins, the values of homogeneous bandwidth and of the coupling constants to high-frequency vibrational modes are not modified with respect to natural human hemoglobin, thus indicating that the local electronic and vibrational properties of the heme-CO complex are not altered by the recombinant procedures. On the contrary, differences in the protein dynamic behavior are observed. The most relevant are those relative to the "polar isosteric" beta Val-67(E11)-->Thr substitution, localized in the heme pocket, which results in decreased coupling with low-frequency modes and increased anharmonic motions. Mutations involving residue beta Lys-144(Hc1) at the C-terminal and residue beta Cys-112(G14) at the alpha 1 beta 1 interface have a smaller effect consisting in an increased coupling with low-frequency modes. Mutations at the beta-N-terminal and at the alpha 1 beta 2 interface have no effect on the dynamic properties of the same heme pocket.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::41a88ec41bda1e4757f03c61ff8e962b https://doi.org/10.1002/prot.340220103 Zobrazit plný text záznamu Plný text