beta-casomorphin-6 + L-isoleucine => beta-casomorphin-7 + H2O
beta-casomorphin-6 + l-isoleucine => beta-casomorphin-7 + h2o
beta-casomorphin-6 + L-isoleucine => beta-casomorphin-7 + H2O
beta-casomorphin-6 + l-isoleucine => beta-casomorphin-7 + h2o