The spectra of equilibrium chain conformation fluctuations of apomyoglobin (apoMb) as a function of folding, from the acid-denatured state at pH 2.6 through the stable molten globule state pH approximately 4.1 to the folded state at pH 6.3, are reported, as measured by fluorescence correlation spectroscopy. The conformational fluctuations, which are detected by quenching of an N-terminal fluore...

Halogenated acetates alone and in combination with dextrose and formaldehyde will protect against heat denaturation of plasma proteins even when plasma is heated for 10 hr. at 60#{176}. Application of this principle would afford reclamation of plasmafrom outdated bloodbank blood. Changes in protein patterns were observedby paper electrophoresis.Other measurementsof denaturation were pH, absorba...

Thermal denaturation profiles of an oligodeoxynucleotide that forms a hairpin structure with a cytidine-rich loop show an unexpected transition at 60 degrees C at pH 5.0 but not at pH 8.0. Analytical ultracentrifugation shows that this transition reflects dimer formation via the interaction of loops from two molecules to form a novel structure termed the h-dimer. The dependence of this structur...

Hyperchromicity measurements are well established to analyse the thermal denaturation behaviour of pure DNA sequences in solution. Here, we show that under appropriate experimental conditions this technique can also be applied to study thermally controlled conformation changes of higher order DNA-protein complexes as for instance metaphase chromosome preparations in suspension. A computer contr...

Human serum albumin (HSA) is an important protein that carries variety of substances like some hormones and drugs in blood. Pharmacological studies of the interaction of many drugs and HSA are reported during several decades, specially recently years. Interaction of cortisol and fluoxetine hydrochloride (FLX) (as a common anti-stress drug) with HSA (as their carrier in blood) has been studied s...

thermal denaturation of p-iactoglobulin type b in the absence and ptencno: of g arious concentrations oftrehalo5e, sucrose and sork toles sugar osmolytes and twlyols were nuyoured hy monitoring changes in theabsorption coefficients at ph 2.0. these measurements gave aliss, or i. mpdpdint of denaturation), al-fis(enthalpy change at ty). and acp (consttun-pressure heal capaciit eh.iltgtii under a...

Purified preparations of cattle rhodopsin have been titrated to various pH, irradiated, and the pH changes followed thereafter until completed. In this way we have obtained the titration curves of rhodopsin, of the immediate product of irradiation, measured within 30 seconds; and of the final product of irradiation (opsin). The rhodopsin preparations display about 54 titratable groups per mole ...

Peptide binding by class II major histocompatibility complex proteins is generally enhanced at low pH in the range of hydrogen ion concentrations found in the endosomal compartments of antigen-presenting cells. We and others have proposed that class II molecules undergo a reversible conformational change at low pH that is associated with enhanced peptide loading. However, no one has previously ...

The effects of pressure, temperature, and pH on the n&\-i@ of purified rabbit skeletal muscle magnesium-activated ATPnsc were measured. The enzyme is rnpidl> and irreversibly inactivated by both temperature and pressure and shows no rvidencc of reversible denaturation. The extent of irreversible inactivation depends on the amount of pressure applied and is largest at the optimum pH of the enzyme.

TK (transketolase) undergoes inactivation during biocatalytic processes due to oxidation, substrate and product inhibition, reactivity of aldehyde substrates, irreversible inactivation at low pH, and dissociation of cofactors. However, the contribution of protein denaturation to each of these mechanisms is not fully understood. The urea-induced reversible denaturations of the apo- and holo-enzy...