Abstract An improved model for calculating the CD of polypeptides has been developed. Excited state wavefunctions were derived from CNDO/S (complete neglect differential overlap, spectroscopic) calculations on N‐methylacetamide. Four discrete peptide‐localized transitions employed: π 0 π*(NV 1 ), π+π* (NV 2 n π*, and ′π*. Inclusion π+π*transition (λ = 140 nm) significantly improves accuracy calculated spectra in 180‐250‐nm region. Spectra computed various helical structures, including...

Understanding the mechanism for sucrose-induced protein stabilization is important in many diverse fields, ranging from biochemistry and environmental physiology to pharmaceutical science. Timasheff Lee [Lee, J. C. & Timasheff, S. N. (1981) Biol. Chem. 256, 7193–7201] have established that thermodynamic of proteins by sucrose due preferential exclusion sugar protein’s surface, which increases chemical potential. The current study measures 1 M a drug, recombinant interleukin receptor...

Abstract Natural and synthetic peptides that contain detectable intramolecular α‐helical structure in aqueous solution have been used to evaluate the helical propensities for common amino acids. Experimental spectroscopic data must be fit a model of helix–coil transition order determine quantitative stability constants each acid. We present here statistical mechanical description helix formation or protein fragments takes into account multiple internal conformations, heterogeneity...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTheoretical study of the contribution aromatic side chains to circular dichroism basic bovine pancreatic trypsin inhibitorMark C. Manning and Robert W. WoodyCite this: Biochemistry 1989, 28, 21, 8609–8613Publication Date (Print):October 17, 1989Publication History Published online1 May 2002Published inissue 17 October 1989https://pubs.acs.org/doi/10.1021/bi00447a051https://doi.org/10.1021/bi00447a051research-articleACS PublicationsRequest reuse...

We have investigated the aggregation of recombinant human granulocyte colony stimulating factor (rhGCSF), a protein that rapidly aggregates and precipitates at pH 6.9 37 degrees C. observed native monomeric rhGCSF reversibly forms dimer under physiological conditions this dimeric species does not participate in irreversible process. Sucrose, thermodynamic stabilizer, inhibits rhGCSF. postulate sucrose acts by reducing concentration structurally expanded species, consistent with hypothesis...

Improved descriptions of the lowest energy excited states tyrosine and phenylalanine side chains have been developed in order to extend capabilities calculating circular dichroism (CD) spectra proteins. Four transitions (Lb, La, Bb, Ba) for each side-chain chromophores were considered, transition monopole charges obtained from a CNDO/S calculation on models representing individual groups. Monopole at midpoints bonds, corresponding maximum charge densities Lb band, vibronic coupling with B La...

Structural differences between two genetic variants of bovine β-lactoglobulins (type A and B) in aqueous solutions were characterized using Fourier transform infrared circular dichroism spectroscopies. To probe structural dynamics, the effects hydrogen−deuterium exchange also compared for proteins. The spectra recorded H2O solution proteins nearly identical conformationlly sensitive amide I region. only exceptions small at band ascribed to a high-wavenumber β-sheet component near 1693 cm-1...

Abstract Osmolytes increase the thermodynamic conformational stability of proteins, shifting equilibrium between native and denatured states to favor state. However, their effects on equilibria within native‐state ensembles proteins remain controversial. We investigated sucrose, a model osmolyte, fluctuations bovine pancreatic ribonuclease A S horse heart cytochrome c . In presence far‐ near‐UV circular dichroism spectra all three were slightly altered indicated that sugar shifted ensemble...

The activation of human mitogen-activated protein kinase 1 (MKK1) is achieved by phosphorylation at Ser218 and Ser222 within a regulatory loop. Partial was replacing these residues with aspartic/glutamic acid. Higher activity obtained introducing four acidic residue substitutions in the loop, indicating that loop stabilize an active configuration introduction negative charge. Activation MKK1 also deleting 44-51, N-terminal to consensus catalytic core. Although substitution this segment...

To obtain further insight into the pathogenesis of amyloidosis and develop therapeutic strategies to inhibit fibril formation we investigated: 1) relationship between intrinsic physical properties (thermodynamic stability hydrogen-deuterium (H-D) exchange rates) propensity human immunoglobulin light chains form amyloid fibrils <i>in vitro</i>; 2) effects extrinsically modulating these on formation. An amyloid-associated protein readily formed vitro</i> had a lower free energy unfolding than...

Congo red (CR) has been reported to inhibit or enhance amyloid fibril formation by several proteins. To gain insight into the mechanism(s) for these apparently paradoxical effects, we studied as a model amyloidogenic protein, dimeric immunoglobulin light chain variable domain. With range of molar ratios CR, i.e. r = [CR]/[protein dimer], investigated aggregation kinetics, conformation, hydrogen-deuterium exchange, and thermal stability protein. In addition, used isothermal titration...