In a surfactant solution, many proteins adopt conformations different from their native states. Such conformational changes are reviewed in terms of the changes in the relative proportions of secondary structures, especially on the bovine serum albumin, intact and disulfide bridgescleaved, and the domain sized fragments of the same protein.
Clarification of the conformation of polymer chains adsorbed at the interfaces is one of the central issues for polymer adsorption study. In this review, we describe the status of study for elucidating the conformation of linear polyelectrolyte chains (sodium polystyrene sulfonate) adsorbed at the solid-liquid interfaces using various experimental techniques. The experimental results allow us to conclude that adsorbed sodium polystyrene sulfonate chains have the loop train-tail conformation, in which the long tail portions govern the thickness of the adsorbed layer normal to the surface.
Neural connections were established between rat lateral geniculate nucleus and visual cortex in organotypic co-culture. Morphological and electrophysiological studies indicate that lamina-s-pecific organization of afferent and efferent neural connections is present in the co-culture. This preparation will be a model system for revealing mechanisms that underlie specific and plastic neural connectivity.
A bee venom, mast cell degranulating peptide (MCD), was synthesized by stepwise formation of the two distinct disulfide bridges. This synthetic peptides with mast cell degrahulating activity MCD induced long-term potentiation (LTP) in the CAl region of hippocampus, while other peptides with mast cell degranulating activity apamin and mastoparan did not. This and other results using derivatives of the synthetic MCD suggest that a rigid structure is required for the LTP induction by MCD. Two antagonists of the N-methyl-D-aspartate (NMDA) receptor, AP5 and MK801, did not block the MCD induced-LTP. Moreover, the efficacy of the synaptic transmission in the slice which had been maximally activated by tetanic stimulation was further potentiated by MCD treatment. These results indicate that two quite distinct pathways for LTP formation exist in the CAl region of the hippocampus.
We studied gustatory transduction in frog taste cells for acid and bitter stimulations. It is concluded that the receptor potential in response to HCl in a taste cell is primarily generated by cations passing through Ca2+ channels at the apical receptor membrane. The receptor potential in response to quinine-HCl of a bitter substance is generated by a secretion of intracellular Cl- ions through the receptor membrane.