Thermodynamic analysis of hydration in human serum heme-albumin

被引：6

作者：

Baroni, Simona ^{[3
]}

Pariani, Giorgio ^{[1
,2
]}

Fanali, Gabriella ^{[1
,2
]}

Longo, Dario ^{[4
,5
]}

Ascenzi, Paolo ^{[6
,7
]}

Aime, Silvio ^{[4
,5
]}

Fasano, Mauro ^{[1
,2
]}

机构：

[1] Univ Insubria, Dept Struct & Funct Biol, I-21052 Busto Arsizio, VA, Italy

[2] Univ Insubria, Ctr Neurosci, I-21052 Busto Arsizio, VA, Italy

[3] Univ Turin, Invento Srl Co Incubator, I-10126 Turin, Italy

[4] Univ Turin, Dept Chem IFM, I-10126 Turin, Italy

[5] Univ Turin, Ctr Mol Imaging CIM, I-10126 Turin, Italy

[6] Univ Roma Tre, Dept Biol, I-00146 Rome, Italy

[7] Univ Roma Tre, Interdept Lab Electron Microscopy, I-00146 Rome, Italy

来源：

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | 2009年 / 385卷 / 03期

关键词：

Human serum albumin; Ferric human serum heme-albumin; Heme-protein hydration; NMR relaxation; MAGNETIC-RELAXATION DISPERSION; MODEL-FREE ANALYSIS; ACID-BINDING SITES; H-1 NMRD PROFILES; ALLOSTERIC MODULATION; HUMAN HEMALBUMIN; LIGAND-BINDING; IRON GEOMETRY; DRUG-BINDING; MYOGLOBIN;

D O I：

10.1016/j.bbrc.2009.05.075

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Ferric human serum heme-albumin (heme-HSA) shows a peculiar nuclear magnetic relaxation dispersion (NMRD) behavior that allows to investigate structural and functional properties. Here, we report a thermodynamic analysis of NMRD profiles of heme-HSA between 20 and 60 degrees C to characterize its hydration. NMRD profiles, all showing two Lorentzian dispersions at 0.3 and 60 MHz, were analyzed in terms of modulation of the zero field splitting tensor for the S = 5/2 manifold. Values of correlation times for tensor fluctuation (tau(nu)) and chemical exchange of water molecules (tau(M)) show the expected temperature dependence, with activation enthalpies of -1.94 and -2.46 +/- 0.2 kJ mol (1), respectively. The cluster of water molecules located in the close proximity of the heme is progressively reduced in size by increasing the temperature, with Delta H = 68 +/- 28 kJ mol(-1) and Delta S = 200 +/- 80 J mol (1) K (1). These results highlight the role of the water solvent in heme-HSA structure-function relationships. (C) 2009 Elsevier Inc. All riglits reserved.

引用

页码：385 / 389

页数：5

共 44 条

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