L-cysteinyl-[protein] + fumarate <=> S-(2-succinyl)-L-cysteinyl-[protein]
l-cysteinyl-[protein] + fumarate <=> s-(2-succinyl)-l-cysteinyl-[protein]
L-cysteinyl-[protein] + fumarate <=> S-(2-succinyl)-L-cysteinyl-[protein]
l-cysteinyl-[protein] + fumarate <=> s-(2-succinyl)-l-cysteinyl-[protein]