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. 2003 Sep;85(3):1538–1547. doi: 10.1016/s0006-3495(03)74586-x

FIGURE 1.

FIGURE 1

The interaction of the CaV1.2 channel α1 carboxy-terminal peptides with Ca2+CaM and apoCaM. CaM (2 μM) was incubated with peptide in increasing peptide:CaM molar ratios before electrophoresis on 20% nondenaturing gels in the presence of either 200 μM Ca2+ (A), or 1 mM EGTA (B). Shown are representative Coomassie-blue stained 20% nondenaturing gels of samples containing CaM and increasing molar ratios of IQ, IQ (AA), C-IQ, C, and A. The first lane in each gel contains CaM only. Peptide:CaM ratios used were 0:1, 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 5:1, 10:1, and 1:0. (C and D) The relative amount of CaM on the gel at each peptide concentration (B) was determined by densitometry and was normalized to CaM in the absence of peptide (B0). The data are plotted as the mean B/B0 ± SE (n = 3) vs. peptide:CaM ratio. C summarizes the results from experiments performed in 200 μM Ca2+ and D summarizes the results from experiments performed in 1 mM EGTA. The graph shows CaM with increasing peptide concentration described by the following symbols: •, C; ⋄, C-IQ; ▿, A; ▵, IQ; and ○, IQ (AA).