4-aminobutanoate + L-arginine => N(2)-(4-aminobutanoyl)-L-arginine + H2O
4-aminobutanoate + l-arginine => n(2)-(4-aminobutanoyl)-l-arginine + h2o
4-aminobutanoate + L-arginine => N(2)-(4-aminobutanoyl)-L-arginine + H2O
4-aminobutanoate + l-arginine => n(2)-(4-aminobutanoyl)-l-arginine + h2o