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Spectroscopic Studies On Human Serum Albumin And Methemalbumin: Optical, Steady-state, And Picosecond Time-resolved Fluorescence Studies, And Kinetics Of Substrate Oxidation By Methemalbumin

Amisha J. Kamal, D. Behere
Published 2002 · Chemistry, Medicine

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Abstract. The nature of the heme environment in methemalbumin, the Fe(III) protoporphyrin IX (heme)-human serum albumin (HSA) complex, was investigated by optical spectroscopy. Comparison of the optical spectra of methemalbumin, ferro-hemalbumin in the absence and presence of 2-methylimidazole, and their carbon monoxide derivatives with horseradish peroxidase (HRP) and its corresponding derivatives indicates that histidine is not present in the first coordination sphere of heme in methemalbumin and that the protein is devoid of a well-defined heme cavity. The complex exhibits peroxidase activity by catalyzing oxidation of 2,2′-azinobis(3-ethylbenzthiazoline-6-sulfonate) by hydrogen peroxide. Its activity (KM=433 µM, molar catalytic activity=0.33 s–1), however, is considerably lower compared to HRP, indicating differences in the heme environments. Fluorescence intensity decays of Trp214 in HSA and methemalbumin, best fitted to a three-exponential model, gave the lifetimes 7.03 ns (30%), 3.17 ns (38%), and 0.68 ns (32%) for HSA and 8.04 ns (1.7%), 2.42 ns (19.7%), and 0.64 ns (78.6%) for methemalbumin. These lifetime values were further confirmed by a model-independent maximum entropy method. Similarity in the lifetimes and variations in the amplitudes suggest that while conformational heterogeneity of HSA is unperturbed on heme binding, redistribution of the populations of the three conformations occurs and the sub-state associated with the shortest lifetime dominates the total population by ~80%. Decay associated spectra (DAS) indicate that the observed lifetime variation with wavelength is predominantly due to ground state heterogeneity, though solvent dipolar relaxation also contributes. Time-resolved fluorescence anisotropy measurements of the Trp214 residue yielded information on motion within the protein together with the whole protein molecule. The binding of heme did not affect the rotational correlation time of the albumin molecule (~20 ns). However, the motion of tryptophan within the protein matrix increased by a factor of ~3 (0.46 ns to 0.15 ns). This indicates that while the overall hydrodynamic volume of the albumin molecule remained the same, tryptophan underwent a more rapid internal rotation because of the efficient energy transfer to the bound heme. Optical studies, analysis of lifetime measurements, DAS, and anisotropy measurements together suggest that heme binds to a surface residue. The rapid internal motion of Trp214 during its excited state lifetime for the ~80% populated conformer of methemalbumin allows the orientation factor, κ2, to approach the average value of 2/3. From the time-resolved fluorescence measurements and the energy transfer calculations on methemalbumin, a Trp214-heme distance of 22 Å was deduced.
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This paper is referenced by
10.1099/MIC.0.28835-0
The HA2 haemagglutinin domain of the lysine-specific gingipain (Kgp) of Porphyromonas gingivalis promotes micro-oxo bishaem formation from monomeric iron(III) protoporphyrin IX.
J. Smalley (2006)
10.4149/gpb_2013011
A viscometric approach of pH effect on hydrodynamic properties of human serum albumin in the normal form.
K. Monkos (2013)
10.1007/0-387-23690-2_6
Luminescence-Based Oxygen Sensors
B. A. Degraff (2005)
10.1016/j.bbrc.2008.02.077
Abacavir and warfarin modulate allosterically kinetics of NO dissociation from ferrous nitrosylated human serum heme-albumin.
P. Ascenzi (2008)
10.1002/9780470508602.CH3
Hydration Dynamics and Coupled Water–Protein Fluctuations Probed by Intrinsic Tryptophan
D. Zhong (2009)
10.1016/j.bpc.2010.03.001
Allostery in a monomeric protein: the case of human serum albumin.
P. Ascenzi (2010)
10.1007/s00775-011-0837-0
Evidence for pH-dependent multiple conformers in iron(II) heme–human serum albumin: spectroscopic and kinetic investigation of carbon monoxide binding
Y. Cao (2011)
10.1016/j.mam.2011.12.002
Human serum albumin: from bench to bedside.
G. Fanali (2012)
10.1371/journal.pone.0058842
Reciprocal Allosteric Modulation of Carbon Monoxide and Warfarin Binding to Ferrous Human Serum Heme-Albumin
A. Bocedi (2013)
10.1529/BIOPHYSJ.106.095026
FRET study of membrane proteins: determination of the tilt and orientation of the N-terminal domain of M13 major coat protein.
P. Nazarov (2007)
10.1042/BJ20031221
A combination of both arginine- and lysine-specific gingipain activity of Porphyromonas gingivalis is necessary for the generation of the micro-oxo bishaem-containing pigment from haemoglobin.
J. Smalley (2004)
Simulation and analysis of FRET in the study of membrane proteins
P. Nazarov (2006)
10.1016/J.MOLLIQ.2019.111456
Interaction of a sphingolipid with human serum albumin in the native, thermally denatured and chemically denatured states: Emission wavelength-dependent photophysical revelation
Swagata Sen (2019)
10.1002/iub.263
Serum heme‐albumin: An allosteric protein
P. Ascenzi (2009)
10.1007/978-88-470-0807-6_12
Human Serum Haeme-albumin: An Allosteric ‘Chronosteric’ Protein
M. Fasano (2008)
10.1016/j.saa.2014.01.073
Pre-denaturing transitions in human serum albumin probed using time-resolved phosphorescence.
K. Sagoo (2014)
10.1515/ctb-2017-0001
Comparison of the Overall Motion Correlation Times of Several Mammalian Serum Albumins in Dilute Solutions Determined on the Basis of Maxwell Effect and the Debye-Stokes-Einstein Equation.
Karol Monkos (2017)
10.1016/J.JPHOTOCHEM.2014.11.012
Effect of fibrillation on the excited state dynamics of tryptophan in serum protein – A time-resolved fluorescence study
Aruna K Mora (2015)
10.15407/UJPE64.4.287
Calculation of the Effective Macromolecular Radii of Human Serum Albumin from the Shear Viscosity Data for Its Aqueous Solutions
O. Khorolskyi (2019)
10.1007/s00775-013-1040-2
Warfarin modulates the nitrite reductase activity of ferrous human serum heme–albumin
P. Ascenzi (2013)
10.1529/BIOPHYSJ.107.113365
Ultrasound-induced calcium oscillations and waves in Chinese hamster ovary cells in the presence of microbubbles.
R. Kumon (2007)
10.1016/j.abb.2019.108075
Labile heme impairs hepatic microcirculation and promotes hepatic injury.
Franziska A Englert (2019)
10.1038/cddiscovery.2015.25
Heme-based catalytic properties of human serum albumin
P. Ascenzi (2015)
10.1016/j.bbagen.2013.03.015
Molecular and practical aspects of the enzymatic properties of human serum albumin and of albumin-ligand complexes.
Ulrich Kragh-Hansen (2013)
10.1074/jbc.M109.010736
Ibuprofen Impairs Allosterically Peroxynitrite Isomerization by Ferric Human Serum Heme-Albumin*
P. Ascenzi (2009)
10.1016/j.saa.2018.03.085
Diketo modification of curcumin affects its interaction with human serum albumin.
S. A. Shaikh (2018)
10.1016/J.BBAPAP.2004.03.006
On the hydrodynamics and temperature dependence of the solution conformation of human serum albumin from viscometry approach.
K. Monkos (2004)
10.1016/J.JPHOTOCHEM.2011.10.024
Excited state intermolecular proton and energy transfer of 1-hydroxypyrene interacting with the human serum albumin protein
N. Carmona (2012)
10.1016/J.CPLETT.2007.01.006
Interaction of curcumin with human serum albumin: Thermodynamic properties, fluorescence energy transfer and denaturation effects
A. Barik (2007)
10.1016/j.bbrc.2009.05.075
Thermodynamic analysis of hydration in human serum heme-albumin.
S. Baroni (2009)
Ultrafast Protein Hydration Dynamics Investigated by Femtosecond Fluorescence Spectroscopy
W. Qiu (2008)
10.1021/acsomega.7b00665
Two-Photon Macromolecular Probe Based on a Quadrupolar Anthracenyl Scaffold for Sensitive Recognition of Serum Proteins under Simulated Physiological Conditions
M. Deiana (2017)
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