Interaction between calmodulin mutant D130V and IQ motif of cardiac Cav1.2 channel
10.12007/j.issn.0258-4646.2025.04.004
- VernacularTitle:钙调蛋白突变体D130V与心肌Cav1.2通道IQ基序的相互作用
- Author:
Luhong TANG
1
;
Yifang LIU
;
Xueting PAN
;
Yingmei XING
;
Liying HAO
;
Jingyang SU
Author Information
1. 中国医科大学药学院临床药理学教研室,沈阳 110122
- Publication Type:Journal Article
- Keywords:
calmodulin;
mutant;
cardiac Cav1.2 channel;
binding ability;
long QT syndrome
- From:
Journal of China Medical University
2025;54(4):306-311
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the binding interaction between the calmodulin(CaM)mutant D130V and the IQ motif of the car-diac Cav1.2 channel.Methods The binding of mutant CaM-D130V to the IQ motif was predicted by fold recognition modeling,homology modeling,and protein docking.The plasmid was transformed into Escherichia coli BL-21 sensory cells via heat shock at 42 ℃ to induce the expression of glutathione S-transferase(GST)fusion protein.The protein was extracted by ultrasonic fragmentation and purified using GS-4B beads.PreScission protease was applied to remove the GST.SDS-PAGE was performed to detect the purity of protein.A GST pull-down assay was conducted to detect the interaction between CaM-D130V and IQ motif.Results Protein docking results showed that both CaM-WT and CaM-D130V could bind to the IQ motif of the cardiac Cav1.2 channel,but the binding sites of the mutant CaM-D130V to the IQ motif were reduced,and its binding conformation was changed compared with the CaM-WT,with decreased binding energy(|S|reduced from 48.086 6 kcal/mol to 47.309 5 kcal/mol).The GST pull-down assay indicated that the binding of CaM-D130V to IQ motif significantly decreased(P＜0.01),and the affinity was significantly reduced at 2 mmol/L Ca2+concentration compared with CaM-WT.Conclusion The reduced binding ability of CaM-D130V to the IQ motif of the cardiac Cav1.2 channel may contribute to functional alterations in the channel.These findings provide a theoretical basis for understanding the pathogenesis of CaM mutant-associated cardio-vascular diseases as well as targeted therapies.
