Tonofilament protein from newborn rat epidermis was found to be antigenically related to mouse keratins. Tonofilament protein, like keratins, could be extracted with 8 M urea in Tris buffer. The yield was enhanced by the presence of dithiothreitol. A higher molecular weight (64,000 dalton) protein antigenically cross-reacting with tonofilament protein but with a slightly different amino acid co...

A new form of fructokinase has been identified from developing maize (Zea mays L.) kernels that utilizes CTP, UTP, and GTP from four to eight times more effectively than ATP at nonlimiting concentrations. Ten millimolar dithiothreitol was necessary to stabilize activity. A second form of fructokinase was nonspecific for nucleoside triphosphate whereas a third form was fairly specific for ATP.

Several factors affecting estrogen receptor assays have been investigated. Pools of rabbit uterus cytosol and human tumor cytosol were utilized to minimize sampling error. Optimum concentration of diethylstilbestrol was found to be 1000 times the highest labeled ligand concentration. Dithiothreitol (DTT) and ionic strength had no effect on receptor value in human tumor cytosols. Optimum pH for ...

Chloroplastic phosphofructokinase, phosphorylase, phosphoglucomutase, and phosphoglucoisomerase in peas are light inactivated. The effect of light on phosphofructokinase is mimicked by dithiothreitol. DCMU, arsenite, and sulfite inhibit light modulation of the enzyme. No effect of light inactivation on the K(m) (fructose-6-P) or pH optima of phosphofructokinase was observed.

Abbreviations: ABC: Ammonium Bicarbonate; AQUA: Absolute Quantification; CV: Coefficient of Variation; DOC: Deoxycholate; DTT: Dithiothreitol; Gdn: Guanidine; IS: Internal Standard; MRM: Multiple Reaction Monitoring; OATP: Organic Anion-Transporting Polypeptide; PMAX: ProteaseMAXTM Surfactant; S.E.M: Standard Error of the Mean; SIL: Stable Isotope Label; SILAC: Stable Isotope Labeling by Amino ...

PoIy(thioglycoloyloxyethyl methacrylate) gel has been prepared. The reactivity of its SH groups was checked with [C]phenyl isothiocyanate. Immobilization of thiol peptides and proteins to a carrier can be performed after its activation with 6,6'-dithiodinicotinic acid. The attached compounds can be released with 50 mmol dm dithiothreitol or can be hydrolyzed with enzymes or acids without decomp...

For fifty years, dithiothreitol (DTT) has been the preferred reagent for the reduction of disulfide bonds in proteins and other biomolecules. Herein we report on the synthesis and characterization of 2,3-bis(mercaptomethyl)pyrazine (BMMP), a readily accessible disulfide-reducing agent with reactivity under biological conditions that is markedly superior to DTT and other known reagents.

2-Amino-4-chloro-5-(-nitrophenylsulfinyl)pentanoic acid (1) has been synthesized and shown to induce mechanism-based inactivation of two pyridoxal phosphate dependent enzymes: (1 ) cystathionine y-synthetase, which catalyzes a y-replacement reaction in bacterial methionine biosynthesis; and (2) methionine y-lyase, which catalyzes a y-elimination reaction in bacterial methionine breakdown. The i...

Highly purified, polymyxin-released, low molecular weight Escherichia coli heat-labile enterotoxin (LT) catalyzed the hydrolysis of NAD to ADP-ribose and nicotinamide. This NAD glycohydrolase activity was stimulated by dithiothreitol and was independent of cellular components. Nicotinamide formation was enhanced by arginine methyl ester > d-arginine congruent with l-arginine congruent with guan...

The molecular weight of a DPN-linked isocitrate dehydrogenase preparation, exhibiting a single major band on polyacrylamide disc gel electrophoresis, has been examined by molecular sieve chromatography. Comparison of the elution volume (V,) of the enzyme with reference proteins of known molecular weight on columns of Sephadex G-ZOO and Sepharose 6B permitted calculation of a molecular weight in...