L-aspartyl-L-lysine(out) <=> L-aspartyl-L-lysine(in)
l-aspartyl-l-lysine(out) <=> l-aspartyl-l-lysine(in)
L-aspartyl-L-lysine(out) <=> L-aspartyl-L-lysine(in)
l-aspartyl-l-lysine(out) <=> l-aspartyl-l-lysine(in)