Analysis of the Polydispersity by Photon Correlation Spectroscopy. Regularization Procedure

Braginskaya, T G; Dobitchin, P D; Ivanova, Mariya; Klyubin, V. V.; Lomakin, Aleksey; Noskin, V. A.; Shmelev, G.E.; Tolpina, S. P.

doi:10.1088/0031-8949/28/1/009

Cited by 40 publications

(23 citation statements)

References 16 publications

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“…A constrained regularization method was used to determine the mean diffusion coefficient,D (20). The mean hydrodynamic radius R h was calculated by using the Stokes-Einstein relationD = k B T/6πηR h , where k B is Boltzmann's constant, T is the absolute temperature, and η is the solvent viscosity.…”

Section: Methodsmentioning

confidence: 99%

Temperature dependence of amyloid β-protein fibrillization

Kusumoto

Lomakin

Teplow

et al. 1998

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

259

277

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Fibrillogenesis of the amyloid -protein (A ) is believed to play a central role in the pathogenesis of Alzheimer's disease. Previous studies of the kinetics of A fibrillogenesis showed that the rate of fibril elongation is proportional to the concentration of monomers. We report here the study of the temperature dependence of the A fibril elongation rate constant, k e , in 0.1 M HCl. The rate of fibril elongation was measured at A monomer concentrations ranging from 50 to 400 M and at temperatures from 4• • • C to 40 • • • C. Over this temperature range, k e increases by two orders of magnitude. The temperature dependence of k e follows the Arrhenius law, k e ‫؍‬ A exp −E A /kT . The preexponential factor A and the activation energy E A are 8 8 8 6 ؋ 10 18 liter/(mol . sec) and 23 kcal/mol, respectively. Such a high value of E A suggests that significant conformational changes are associated with the binding of A monomers to fibril ends.

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Section: Methodsmentioning

confidence: 99%

Temperature dependence of amyloid β-protein fibrillization

Kusumoto

Lomakin

Teplow

et al. 1998

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

259

277

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“…Ten measurements were taken for each sample. The signal was processed by a Langley Fold model 1096 correlator, and data analysis was performed using a regularization procedure (36), modified for the analysis of the goniodyne autocorrelation function (37). The autocorrelation function was utilized to reconstruct the distribution of the scattering particles over diffusion coefficients from fluctuations in the scattering intensity of the protein solution.…”

Section: Methodsmentioning

confidence: 99%

A Conformational Change in the Human Major Histocompatibility Complex Protein HLA-DR1 Induced by Peptide Binding

et al. 1999

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To investigate a conformational change accompanying peptide binding to class II MHC proteins, we probed the structure of a soluble version of the human class II MHC protein HLA-DR1 in empty and peptide-loaded forms. Peptide binding induced a large decrease in the effective radius of the protein as determined by gel filtration, dynamic light scattering, and analytical ultracentrifugation. It caused a substantial increase in the cooperativity of thermal denaturation and induced alterations in MHC polypeptide backbone structure as determined by circular dichroism. These changes suggest a condensation of the protein around the bound peptide. An antibody specific for 58-69 preferentially bound the empty protein, indicating that the peptide-induced conformational change involves the -subunit helical region. The conformational change may have important implications for the mechanisms of intracellular antigen presentation pathways.

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“…The onset of aggregation, hydrodynamic radii, and evolution of the size distribution of particles were studied by quasielastic light scattering with a 144-channel Langley-Ford (Amherst, MA) model 1097 correlator and a Spectra-Physics model 164 argon laser. Further discussion on this subject can be found elsewhere (10,11).…”

Section: Se-hplcmentioning

confidence: 99%

Molecular basis of a progressive juvenile-onset hereditary cataract

Pande

Asherie

et al. 2000

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

130

184

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We have expressed recombinant wild-type human ␥D crystallin (HGD) and its Arg-14 to Cys mutant (R14C) in Escherichia coli and show that R14C forms disulfide-linked oligomers, which markedly raise the phase separation temperature of the protein solution. Eventually, R14C precipitates. In contrast, HGD slowly forms only disulfide-linked dimers and no oligomers. These data strongly suggest that the observed cataract is triggered by the thiolmediated aggregation of R14C. The aggregation profiles of HGD and R14C are consistent with our homology modeling studies that reveal that R14C contains two exposed cysteine residues, whereas HGD has only one. Our CD, fluorescence, and differential scanning calorimetric studies show that HGD and R14C have nearly identical secondary and tertiary structures and stabilities. Thus, contrary to current views, unfolding or destabilization of the protein is not necessary for cataractogenesis.I n the hereditary, juvenile-onset cataract described by Stefan et al. (1), the lens, which is clear at birth, develops punctate opacities progressively, such that by two years of age the cataract is readily detectable, and matures by early childhood or adolescence. The punctate opacities seen in this cataract are in the nucleus and inner cortex, regions of the lens that are enriched in the ␥-crystallins. In the human lens, only two members of the ␥-crystallin family, ␥C and ␥D, are expressed in appreciable amounts, and only ␥D crystallin continues to be expressed until late childhood (2, 3). In affected individuals, a single point mutation has been identified in the ␥D crystallin gene that corresponds to the substitution of Arg-14 by a Cys. The identification of this mutation and the parallel between the time course of the pathology and the physiological expression of human ␥D crystallin strongly implicate the Arg-14 3 Cys mutant of ␥D in the development of this cataract. However, the molecular mechanism invoked to explain the observed opacity has been speculative (1).In the past, it has not been possible to conduct detailed studies on human ␥D crystallin because of the difficulty of obtaining sufficient quantities of pure protein from young, normal human lenses (4). Therefore, to characterize the normal protein thoroughly and investigate the mechanism by which the Arg-14 3 Cys mutation in ␥D could lead to cataract, we cloned and expressed human ␥D crystallin and its Arg-14 3 Cys mutant in Escherichia coli. Both the wild-type recombinant ␥D crystallin (HGD) and its Arg-14 3 Cys mutant (R14C) folded efficiently in E. coli and accumulated as soluble proteins. We isolated and purified the HGD and R14C proteins and determined their solution properties. Our results suggest that the disulfidecrosslinked oligomerization of R14C is responsible for the observed cataract. Furthermore, such oligomerization occurs without significant change in protein structure, conformation, and stability. Materials and MethodsCloning, Expression, and Isolation of Proteins. The human ␥D crystallin coding sequence was amplif...

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Analysis of the Polydispersity by Photon Correlation Spectroscopy. Regularization Procedure

Cited by 40 publications

References 16 publications

Temperature dependence of amyloid β-protein fibrillization

Temperature dependence of amyloid β-protein fibrillization

A Conformational Change in the Human Major Histocompatibility Complex Protein HLA-DR1 Induced by Peptide Binding

Molecular basis of a progressive juvenile-onset hereditary cataract

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