Poly(methyl methacrylate) in the brush form is grown from the surface of magnetite nanoparticles by ambient temperature atom transfer radical polymerization (ATATRP) using a phosphonic acid based initiator. The surface initiator was prepared by the reaction of ethylene glycol with 2-bromoisobutyrl bromide, followed by the reaction with phosphorus oxychloride and hydrolysis. This initiator is an...

The synthesis of a macro-initiator from cellulose in mixtures of zincbased ionic liquid and polar solvents including deep eutectic solvent, dimethylformamide, acetone, and tetrahydrofuran (THF) was studied. The results of FTIR and NMR spectroscopies indicated that the cellulose-based macro-initiator can only be obtained in an inert ether solvent, THF. When the amounts of cellulose and zinc-base...

A novel nano-initiator containing kojic acid moiety, [5-(benzyloxy)-4-oxo-4H-pyran-2-yl)methyl-2-bromo-2-methylpropanoate was synthesized by the reaction of 5-(benzyloxy)-2-(hydroxymethyl)-4H-pyran-4-one with 2-bromoisobutyryl bromide in triethylamine and used as initiator in the atom transfer radical polymerization (ATRP) of styrene and methyl methacrylate in the presence of Cu(0)/CuCl2and N,N...

In all organisms, translational initiation takes place on the small ribosomal subunit and two classes of methionine tRNA are present. The initiator is used exclusively for initiation of protein synthesis while the elongator is used for inserting methionine internally in the nascent polypeptide chain. The crystal structure of Escherichia coli initiator tRNA(f)(Met) has been solved at 3.1 A resol...

Proline dehydrogenase (PRODH) and Delta(1)-pyrroline-5-carboxylate dehydrogenase (P5CDH) catalyze the two-step oxidation of proline to glutamate. They are distinct monofunctional enzymes in all eukaryotes and some bacteria but are fused into bifunctional enzymes known as proline utilization A (PutA) in other bacteria. Here we report the first structure and biochemical data for a monofunctional ...

A major regulatory mechanism evolved by microorganisms to combat stress is the regulation mediated by (p)ppGpp (the stringent response molecule), synthesized and hydrolyzed by Rel proteins. These are divided into bifunctional and monofunctional proteins based on the presence or absence of the hydrolysis activity. Although these proteins require Mg(2+) for (p)ppGpp synthesis, high Mg(2+) was sho...

Proline dehydrogenase (PRODH) and Δ(1)-pyrroline-5-carboxylate (P5C) dehydrogenase (P5CDH) catalyze the four-electron oxidation of proline to glutamate via the intermediates P5C and l-glutamate-γ-semialdehyde (GSA). In Gram-negative bacteria, PRODH and P5CDH are fused together in the bifunctional enzyme proline utilization A (PutA) whereas in other organisms PRODH and P5CDH are expressed as sep...

Caspases play a critical role in the execution of metazoan apoptosis and are thus attractive therapeutic targets for apoptosis-associated diseases. Here we report that baculovirus P49, a homolog of pancaspase inhibitor P35, prevents apoptosis in invertebrates by inhibiting an initiator caspase that is P35 insensitive. Consequently P49 blocked proteolytic activation of effector caspases at a uni...

Activation of an initiator caspase is essential to the execution of apoptosis. The molecular mechanisms by which initiator caspases are activated remain poorly understood. Here we demonstrate that the autocatalytic cleavage of Dronc, an important initiator caspase in Drosophila, results in a drastic enhancement of its catalytic activity in vitro. The autocleaved Dronc forms a homodimer, whereas...

Polymers with a low molecular weight derived from soybean oil have been prepared in a supercritical carbon dioxide medium by cationic polymerization. Boron trifluoride diethyl etherate was used as an initiator. Influences of polymerization temperature, amount of initiator, and carbon dioxide pressure on the molecular weight were investigated. It is shown that the higher polymerization temperatu...