Calpeptin ameliorated SNAP-25 cleavage and promoted the formation of the SNARE complex. (A) The mRNA expression of syntaxin 1, SNAP-25, and VAMP-2 normalized with β-actin. (B) The protein products of syntaxin 1, N-terminal of SNAP-25, and C-terminal of SNAP-25, VAMP-2, and β-actin. (C) Semi-quantitative analysis of the protein expression of syntaxin 1, N-terminal of SNAP-25, and C-terminal of SNAP-25 and VAMP-2, normalized with β-actin. (D) The protein products of the SNARE complex. (E) Semi-quantitative analysis of the protein expression of SNARE complex protein normalized with syntaxin 1 protein. Data represent mean ± standard deviation, n = 4. * p < 0.05 and ** p < 0.01 indicate significant differences from controls; #
p < 0.01 and ##
p < 0.01 indicate significant differences from the 100 μΜ Mn-treated group.