The organization of actin filaments into large ordered structures is a tightly controlled feature of many cellular processes. However, the mechanisms by which actin filament polymerization is initiated from the available pool of profilin-bound actin monomers remain unknown in plants. Because the spontaneous polymerization of actin monomers bound to profilin is inhibited, the intervention of an ...

Arp2/3 complex plays a key role in regulated actin polymerization. A recent study has revealed marked differences in the ability of two nucleation-promoting factors - N-WASP and Scar/WAVE1 - to activate the Arp2/3 complex. Further insights have come from determination of the Arp2/3 crystal structure.

Cyclopentalljphenanthrene titanium trichloride and its 2-methyl and phenyl derivatives were synthesized; the crystal structure of the 2-mcthyl-substituted complex was determined by X-ray diffraction analysis. In the presence of methylalumoxane (MAO), these complexes give highly active catalysts for the syndiotactic polymerization of styrene; the 2-phenyl-substituted complex exceeds all previous...

The recent selection of a complex ribozyme capable of general polymerization on a template in trans has revealed how catalysts may have arisen from one another in the RNA world.

Herein the enantio-selective polymerization of diacetylene (DA) units in the discotic hydrogen-bonding complex is carried out in an asymmetric reaction field consisting of the lamellar columnar LC phase and CPUL stimulus.

The hybrid polymer was synthesized by a radical polymerization of a B(12) derivative and a Ru complex having styrene moieties in each peripheral position, and the hybrid polymer showed photocatalytic activity for molecular transformation with visible light irradiation.

A series of zinc silylamido complexes bearing claw-type multidentate aminophenolate ligands, [LZnN(SiMe(3))(2)] (L = -OAr(1)-CH(2)N[(CH(2))(n)NR(2)]CH(2)Ar(2), n = 2 or 3; R = Me or Et (1a-3a, 5a, 7a and 8a); L = -OC(6)H(2)-4,6-(t)Bu(2)-2-CH(2)N[(CH(2))(2)OMe](2) (9a)), have been synthesized via the reaction of Zn[N(SiMe(3))(2)](2) and 1 equiv. of corresponding aminophenol. The reaction of Zn[N...

Several systems in organic chemistry are so large and complex that formulating the rate equations for their kinetics is difficult. Examples include polymerization of bio-derived materials, such as natural oils resins, metabolic oxidation reactions, Krebs cycle. The challenge lies diversity reaction products growth size, which may be unbounded due to polymerization-like reactions. Here we demons...

Optimization of a semicontinuous emulsion polymerization reaction is carried out using a mathematical model derived from first principles to represent the process. Iterative Dynamic Programming (IDP), being a straightforward procedure that allows the implementation of optimization constraints, is an attractive tool to optimize highly complex and nonlinear equation systems such as those that are...

Using laser fluctuation spectroscopy, a technique that measures particle size change in solution, the kinetics of fibrin clot formation from fibrinogen can be studied. With this technique the effect of calcium on the three distinguishable phases of clot formation, (1) proteolysis of fibrinogen, (2) fibrinogen-fibrin monomer complex formation, and (3) fibrin monomer polymerization, were investig...