AIMTo optimize the method of investigating structural integration between proteins and study the integration between arrhythmia related proteins in molecular level.

METHODSImmunostaining the normal ventricular myocytes was used to observe the distribution of connexin 43 and muscarinic acetylcholine receptor (mAChR). The five mAChR subtypes were precipitated using immunoprecipitation. Then, SDS-PAGE and Western blotting with the anti-connexin 43 antibody were performed to observe whether they were structurally integrated. Further, different concentrations of detergent were used to observe whether this relationship could be broken.

RESULTSThe five subtypes of mAChR existed in the cardiac myocyte of the rat, and all the five mAChR subtypes combined with connexin 43. In the normal rat ventricular myocyte membrane, connexin 43 and M3 receptor are co-located. When adding certain concentration of detergent to the membrane protein, the integration between M3 receptor and connexin 43 was broken, and the phosphorylated form of connexin 43 integrated with M3 receptor.

CONCLUSIONThe results indicated that the structural integration between mAChR and phosphorylation of connexin 43 existed in rat ventricular myocardium, and this integration could be broken by certain concentration of detergent.