Lateral migration and focusing of colloidal particles and DNA molecules under viscoelastic flow.

Much difficulty has been encountered in manipulating small-scale materials, such as submicron colloidal particles and macromolecules (e.g., DNA and proteins), in microfluidic devices since diffusion processes due to thermal (Brownian) motion become more pronounced with decreasing particle size.

Sustained delivery of human growth hormone using a polyelectrolyte complex-loaded thermosensitive polyphosphazene hydrogel.

A combined system of polyelectrolyte complex (PEC) and injectable, biodegradable and thermosensitive poly(organophosphazene) hydrogel has been suggested as an injectable depot for a controlled and sustained delivery of human growth hormone (hGH) to improve patient compliance. PEC was prepared by mixing polycations with hGH to suppress diffusion of hGH from the hydrogel through an enlargement of the hydrodynamic size of hGH. Among the polycations, poly-L-arginine (PLA) formed a large complex with hGH and its size increased as the amount of PLA increased.

Cationic and thermosensitive protamine conjugated gels for enhancing sustained human growth hormone delivery.

Thermosensitive and cationic poly(organophosphazenes) were designed and synthesized for the sustained delivery of human growth hormone (hGH) charged negatively at the physiological conditions to enhance greatly patient convenience and to improve efficacy and stability. Protamine for a complex formation with hGH was chosen and conjugated to carboxylic acid-terminated poly(organophosphazenes) by a covalent amide linkage. The aqueous solution of the cationic polymer conjugates formed a gel at 37 degrees C regardless of hGH presence.

Role of the GYVG pore motif of HslU ATPase in protein unfolding and translocation for degradation by HslV peptidase.

HslVU is an ATP-dependent protease consisting of HslU ATPase and HslV peptidase. In an HslVU complex, the central pores of HslU hexamer and HslV dodecamer are aligned and the proteolytic active sites are sequestered in the inner chamber of HslV. Thus, the degradation of natively folded proteins requires unfolding and translocation processes for their access into the proteolytic chamber of HslV.

Molecular architecture of the ATP-dependent CodWX protease having an N-terminal serine active site.

CodWX in Bacillus subtilis is an ATP-dependent, N-terminal serine protease, consisting of CodW peptidase and CodX ATPase. Here we show that CodWX is an alkaline protease and has a distinct molecular architecture. ATP hydrolysis is required for the formation of the CodWX complex and thus for its proteolytic function.