+ - Driven Molecular Hammer . Jill
نویسندگان
چکیده
In the current understanding of exocytosis at the nerve terminal, the C2A domain of synaptotagmin is presumed to bind Ca and the membrane in a stepwise fashion: cation then membrane as cation increases the affinity of protein for membrane. Fluorescence spectroscopy data was gathered over a variety of lipid and Ca concentrations, enabling the rigorous application of microscopic binding models derived from partition functions to differentiate between Ca and phosphatidylserine (PS) contributions to binding. The present data is in variance with previously published models, which were based on the Hill approximation. Rather, it is consistent with two forms of cooperativity that modulate the responsiveness of C2A: in Ca binding to a network of three cation sites and in interaction with the membrane surface. We suggest synaptotagmin I C2A is preassociated with the synaptic vesicle membrane or nerve terminal. In this state, upon Ca influx the protein will bind the three Ca ions immediately and with high cooperativity. Thus, membrane association creates a high affinity Ca switch that is the basis for the role of synaptotagmin I in Ca-regulated exocytosis. Based on this model, we discuss the implications of protein-induced PS demixing to the exocytotic process.
منابع مشابه
Numerical hydrodynamic simulations of molecular outflows driven by Hammer jets
Very young protostars eject collimated jets of molecular gas. Although the protostars themselves are hidden, some of their properties are revealed through the jet dynamics. We here model velocity shear, precession, pulsation and spray within dense jets injected into less-dense molecular clouds. We investigate the Hammer Jet, for which extreme velocity variations as well as strong ripping and sp...
متن کاملIdentification of BKCa channel openers by molecular field alignment and patent data-driven analysis
In this work, we present the first comprehensive molecular field analysis of patent structures on how the chemical structure of drugs impacts the biological binding. This task was formulated as searching for drug structures to reveal shared effects of substitutions across a common scaffold and the chemical features that may be responsible. We used the SureChEMBL patent database, which prov...
متن کاملShape of mole nose providing minimum axial resistance
Introduction: As a carrier of different sensors, moles can penetrate into the regolith automatically and keep investigating the subsurface environment continuously. In this section, features of several moles with different applications are introduced to explain why we choose a hammer-driven mole to study. Mole driven by a hammer: In this section, the penetrating principle of a hammer-driven mol...
متن کاملA Survey of Analogue-to-Digital Converters
equipment driven by the printer. When the two codes compare, the hammer is en~r gized. The important thing is to get the print hammer thyratron fired at the right time. As long as the sum total of all the operations you do beforehand achieves that, you get the right character. Lt. R. S. Weinberg (Air Materiel Command, United States Air Force): Can you relate something of the service experience...
متن کامل