Mechansim Of PH Interact To Cav1.2 Calcium Channel

With the rapid development of our country,we will face more and more opportunities and challenges,in order to seize the opportunity to be succeeful,people began to overdraw their own body and mind,stay up all night and excessively use of the brain,which caused by cerebral hypoxia,which leads to the learning and work efficiency is reduced,the response is slow,nocturnal sleep disorder results.And brain hypoxia can cause acidosis.Acidosis is known to produce harmful effects on cardiac function,including decreased contractility,arrhythmia,and resistance to the effects of catecholamines.Acid poisoning phenomenon of myocardial cells is a major cause of cell decreased myocardial contractility,intracellular pH decrease would seriously disrupt every contraction process,and seriously affect the ability of myocardial cell expansion,causing serious damage to the function of the heart function and metabolic disorders can lead to heart muscle cells.Cav1.2 calcium channel are the major route of the Ca2+ enter in many cell.Voltage-gated Ca2+ channels play an important role in cellular excitation related to rhythmic firing,muscle contraction,synaptic transmission and gene expression.CaM also play an important role in modulating many physiological activities,such as various enzymes,muscle contraction,muscle contraction,relaxation,and gene expression.Studies have shown that the C terminals of Cavl.2 calcium channels have CaM binding sites,namely preIQ and IQ regions,and the EF and Hand sequences which is prior to the preIQ sequence also has influence on the binding of CaM and channels.It is proposed in this paper that pH affects the binding of CaM and channels,thus affecting the channel activity.First of all,the following experiments have been done using molecular biology pulldown experimental technique:(1)CaM bind to Cav1.2 calcium channel C-terminal in the condition of different pH(5,6,7,8,9),experimental results show that in low calcium and high calcium conditions,with the decrease of pH,the combination of CaM and calcium channel is increased.(2)pH in order to determine which one is the impact of the specific binding sites which affect the binding of CaM and calcium ion channel,we use CaM1234 and CT1 combination,the results show that the pH effect is not four Ca2+ CaM binding site which affects the amount of.(3)In order to determine whether pH affected EF hand,thus affecting the binding of CaM and channels,by performing pulldown experiments with CaM and CT1B.The results showed that shortened CT1 fragments did not eliminate the effects of pH on CaM and Ca2+channel binding.Therefore,we propose that the hypothesis may affect the conformation of the CaM binding site,thereby affecting the binding capacity.At the same time,the computer simulation technique is used to carry out the molecular dynamics simulation of the object under study.The main work is as follows:(1)homology modeling:to establish the following four protein fragments EF,Hand,EF+preIQ,preIQ+IQ,IQ,and then to optimize the model and evaluate the model for the next step of protein docking simulation.(2)molecular docking:using Zdock software,the docking of the established C end fragment with CaM was carried out,and the highest part of the docking fraction was found.These were the two parts of preIQ and IQ.(3)interaction effect analysisThis paper through the experiments exclude the possibility of the CaM1234 and the EF Hand of Cavl.2 calcium channels effect channel activity.Futhermore,we found 114GIu maybe the influence factor to affect by simulation.This topic has certain guiding significance for further understanding of Cav1.2 calcium channel.