| Products/Services Used | Details | Operation |
|---|---|---|
| PCR Cloning and Subcloning | The gene for H. sapiens NaV1.4 CTerm Long (SCN4A; a.a. 1599–1764; ENF…GDD) in a pGEX-6- P1 plasmid with an N-terminal GST tag was purchased from Genscript, together with the gene for full-length mammalian calmodulin (R. norvegicus CALM2; 100% amino acid identity with H. sapiens CaM) cloned into a pET24b plasmid4 were used to co-transform BL21-CodonPlus RIL E. coli (Agilent) cells. T The 20-mer peptide corresponding to NaV1.4 residues 1312–1331 (100% identity with NaV1.5 residues 1487–1506) was synthesized (MTEEQKKYYNAMKKLGSKKP). This peptide has 30% identity with the DIII–DIV linker seen in NavPaS. Synthesis was performed by Genscript and judged to be over 95% pure. | Get A Quote |
Skeletal muscle voltage-gated Na+ channel (NaV1.4) activity is subject to calmodulin (CaM) mediated Ca2+-dependent inactivation; no such inactivation is observed in the cardiac Na+ channel (NaV1.5). Taken together, the crystal structures of the NaV1.4 C-terminal domain relevant complexes and thermodynamic binding data presented here provide a rationale for this isoform difference. A Ca2+-dependent CaM N-lobe binding site previously identified in NaV1.5 is not present in NaV1.4 allowing the N-lobe to signal other regions of the NaV1.4 channel. Consistent with this mechanism, removing this binding site in NaV1.5 unveils robust Ca2+-dependent inactivation in the previously insensitive isoform. These findings sugge... More
