An investigation by dielectric methods of hydration in myoglobin solutions

Grant, E H; Mitton, Barbara G. R.; South, G. P.; Sheppard, R J

doi:10.1042/bj1390375

Cited by 49 publications

(27 citation statements)

References 14 publications

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“…However, the form of the boundary between the water and the macromolecular dipole may mean that the appropriate viscosity is different from the bulk value [20]. The irregular nature of the protein surface may, for instance, introduce greater friction than appropriate for the ball-bearing representation on which dielectric relaxation model is based [20]; this would create a larger relaxation time than expected, and, in this case, the macromolecular dipole may be attributed to the AFPIII monomer and its hydration shell. From these results, both options are possible, and this question must await further investigations involving direct methods for the determination of the association state of the AFPIII.…”

Section: Discussionmentioning

confidence: 99%

Electro-Optical Properties Characterization of Fish Type III Antifreeze Protein

2007

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Antifreeze proteins (AFPs) are ice-binding proteins that depress the freezing point of water in a non-colligative manner without a significant modification of the melting point. Found in the blood and tissues of some organisms (such as fish, insects, plants, and soil bacteria), AFPs play an important role in subzero temperature survival. Fish Type III AFP is present in members of the subclass Zoarcoidei. AFPIII are small 7-kDa-or 14-kDa tandem-globular proteins. In the present work, we study the behavior of several physical properties, such as the low-frequency dielectric permittivity spectrum, circular dichroism, and electrical conductivity of Fish Type III AFP solutions measured at different concentrations. The combination of the information obtained from these measurements could be explained through the formation of AFP molecular aggregates or, alternatively, by the existence of some other type of interparticle interactions. Thermal stability and electrooptical behavior, when proteins are dissolved in deuterated water, were also investigated.

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Section: Discussionmentioning

confidence: 99%

Electro-Optical Properties Characterization of Fish Type III Antifreeze Protein

2007

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“…Protein contribution to the nuclear magnetic relaxation rates T,-' of solvent 1H (0) and 2H (-) in aqueous solutions of hemocyanin (containing 11.5 One must consider the possibility that the nuclear relaxation effects are related to the "traditional" hydration layer surrounding a protein, that layer which must be associated with the protein molecule in the analysis of hydrodynamic data (e.g., dielectric dispersion, diffusion, sedimentation velocity) to account for the effective hydrodynamic size of the protein molecules. From the work of Kuntz (23), who detects a liquid water layer surrounding protein molecules in frozen solutions, and from high frequency dielectric studies (24)(25)(26), it appears that the dynamic behavior of the water molecules in the hydration layer is akin to that of the bulk, but with the rotational tumbling slowed one or two orders of magnitude to something of the order of 10-9-10-10 sec. still fast compared to the relaxation time for rotational motion of the protein.…”

Section: Methodsmentioning

confidence: 99%

Protein-water interaction studied by solvent 1H, 2H, and 17O magnetic relaxation.

Koenig¹,

Hallenga²,

Shporer³

1975

Proc. Natl. Acad. Sci. U.S.A.

103

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Previous studies of the magnetic field de- Solvent proton relaxation in protein solutions can be accounted for reasonably well within the framework of a simple model of water exchange between the bulk solvent, in which the protons are assumed not to interact with the solute, and regions on or near the protein where the rotational motion of the protein molecules is conveyed to the water molecules. If it is assumed that the water molecules in the latter region attach rigidly to the protein, then one can readily estimate (1) the number n of such attachment sites to be about 3 for lysozyme and to increase at least as fast as the surface area for larger proteins (K. Hallenga and S. H. Koenig, to be published). If the attachment is assumed not rigid, the derived value of n is greater by a small factor, but is still-and this is the major unsettling feature of this simple two-site model-only a few percent of the number of water molecules in the first hydration layer (1). The nature of such special sites is difficult to conceive.From the data for proton relaxation, one can only set fairly wide limits on the value (or distribution of values) of TM, the mean lifetime of a water molecule on the protein and a quantity which is a feature of the model itself. The application of the model gives TM > TR 10-7 sec, and TM < Tipr -10-4 sec, the relaxation time of the protons when on the protein. In an attempt to get a better measurement of TM, as well as to test other predictions of the models, we measured and report here comparisons of the magnetic field dependence of the relaxation rate of 170 in solutions of protein in 17O-enriched water, and deuterons in 2H20 solutions, with the proton data. Since deuterons in water relax about 10 times faster than protons, and 170 nuclei about 100 times faster than deuterons, the upper limit on the model value for TM is drastically reduced and the range for TM is drastically narrowed. We have also made measurements on an extremely large protein-hemocyanin associated to a M.W. of 9 X 106-in order to increase the lower limit of TrM. The experiments were quite successful in that -TM was squeezed into nonexistence: i.e., the data reported below cannot be explained by a simple two-region model with a defined life-

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“…Myoglobin is a single chain globular protein of 153 amino acids containing heme ͑iron containing porphyrin͒ prosthetic group in the center, around which remaining apoprotein folds. [43][44][45][46][47][48][49] It has molecular weight of 16.7 kDa. [44][45][46]48 It is the primary oxygen carrying pigment of muscle tissues.…”

Section: Dielectric Myoglobin Modelmentioning

confidence: 99%

“…[43][44][45][46][47][48][49] It has molecular weight of 16.7 kDa. [44][45][46]48 It is the primary oxygen carrying pigment of muscle tissues. Myoglobin has isoelectric point at pH 8.5, 3 where it acts as a neutral particle.…”

Section: Dielectric Myoglobin Modelmentioning

confidence: 99%

Modeling of dielectrophoretic transport of myoglobin molecules in microchannels

Gunda

Mitra

2010

Biomicrofluidics

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Myoglobin is one of the premature identifying cardiac markers, whose concentration increases from 90 pg/ml or less to over 250 ng/ml in the blood serum of human beings after minor heart attack. Separation, detection, and quantification of myoglobin play a vital role in revealing the cardiac arrest in advance, which is the challenging part of ongoing research. In the present work, one of the electrokinetic approaches, i.e., dielectrophoresis ͑DEP͒, is chosen to separate the myoglobin. A mathematical model is developed for simulating dielectrophoretic behavior of a myoglobin molecule in a microchannel to provide a theoretical basis for the above application. This model is based on the introduction of a dielectrophoretic force and a dielectric myoglobin model. A dielectric myoglobin model is developed by approximating the shape of the myoglobin molecule as sphere, oblate, and prolate spheroids. A generalized theoretical expression for the dielectrophoretic force acting on respective shapes of the molecule is derived. The microchannel considered for analysis has an array of parallel rectangular electrodes at the bottom surface. The potential and electric field distributions are calculated using Green's theorem method and finite element method. These results also compared to the Fourier series method, closed form solutions by Morgan et al. ͓J. Phys. D: Appl. Phys. 34, 1553 ͑2001͔͒ and Chang et al. ͓J. Phys. D: Appl. Phys. 36, 3073 ͑2003͔͒. It is observed that both Green's theorem based analytical solution and finite element based numerical solution for proposed model are closely matched for electric field and square electric field gradients. The crossover frequency is obtained as 40 MHz for given properties of myoglobin and for all approximated shapes of myoglobin molecule. The effect of conductivity of medium and myoglobin on the crossover frequency is also demonstrated. Further, the effect of hydration layer on the crossover frequency of myoglobin molecules is also presented. Both positive and negative DEP effects on myoglobin molecules are obtained by switching the frequency of applied electric field. The effect of different shapes of myoglobin on DEP force is studied and no significant effect on DEP force is observed. Finally, repulsion of myoglobin molecules from the electrode plane at 1 KHz frequency and 10 V applied voltage is observed. These results provide the ability of applying DEP force for manipulating nanosized biomolecules such as myoglobin.

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An investigation by dielectric methods of hydration in myoglobin solutions

Cited by 49 publications

References 14 publications

Electro-Optical Properties Characterization of Fish Type III Antifreeze Protein

Electro-Optical Properties Characterization of Fish Type III Antifreeze Protein

Protein-water interaction studied by solvent 1H, 2H, and 17O magnetic relaxation.

Modeling of dielectrophoretic transport of myoglobin molecules in microchannels

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