The role of GTP hydrolysis in microtubule dynamics has been reinvestigated using an analogue of GTP, guanylyl-(alpha, beta)-methylene-diphosphonate (GMPCPP). This analogue binds to the tubulin exchangeable nucleotide binding site (E-site) with an affinity four to eightfold lower than GTP and promotes the polymerization of normal microtubules. The polymerization rate of microtubules with GMPCPP-...

A comprehensive picture of structural changes of cellulosic biomass during enzymatic hydrolysis is essential for a better understanding of enzymatic actions and development of more efficient enzymes. In this study, a suite of analytical techniques including sum frequency generation (SFG) spectroscopy, infrared (IR) spectroscopy, x-ray diffraction (XRD), and x-ray photoelectron spectroscopy (XPS...

A monoclonal antibody, 7B3, specific to the a subunit of the mitochondrial ATPase-ATP synthase inhibited the rate of ATP hydrolysis by either soluble F1 or electron transport particles up to a maximum of 75%. However, 7B3 did not modify the rate of ITP hydrolysis. In addition, the apparent K , for MgATP extrapolated at high ATP concentrations had the same value in the absence as in the presence...

The enzymatic hydrolysis and fermentation of reed canary grass, harvested in the spring or autumn, and barley straw were studied. Steam pretreated materials were efficiently hydrolysed by commercial enzymes with a dosage of 10-20FPU/g d.m. Reed canary grass harvested in the spring was hydrolysed more efficiently than the autumn-harvested reed canary grass. Additional β-glucosidase improved the ...

Supernatant from a sonicated macerate of eggs of Heterodera glycines hydrolyzed L-leucine beta-naphthylamide and L-leucine 7-amido-4-methylcoumarin. Rate of substrate hydrolysis was influenced by pH and increased with the duration of incubation. A Michaelis-Menten constant of 0.15 mM was obtained. Rate of substrate hydrolysis was decreased by freezing egg supernatant for 26 days or heating abov...

The hydrolysis of iminohydantoins generates the same tetrahedral intermediate as that obtained in the cyclization of hydantoic acid amides to hydantoins. The ratio of the products of imine hydrolysis under kinetic control is determined by the relative height of the barriers of the breakdown of to amide or to hydantoin. Thus the partitioning of products unequivocally proves which is the rate det...

Recent studies from our laboratory (Yancey, P.G., and R. W. St. Clair. 1992. Arterioscler. Thromb. 12: 1291-1304) have shown that cultured peritoneal macrophages from White Carneau (WC) pigeons clear cholesteryl esters at a slower rate than do macrophages from Show Racer (SR) pigeons (9% per 24 h vs. 42% per 24 h, respectively) when incubated in the presence of a cholesterol acceptor apo high d...

Pseudomonas aeruginosa EF2, ATCC 9027 and ATCC 19660 were grown in a continuous culture under Tween 80 (polyoxyethylene sorbitan monooleate) limitation and optimum conditions (pH 6.5, 37°C at dilution rate of 0.05/h). Culture supernatants were carefully removed and stored at -20°C. To purify the lipases, the culture supernatant was reduced in volume to approximately 10 mL by an ultrafiltra...