Carnitine (1, 3-hydroxy-4-trimethylammoniobutyrate) is essential as a donor and acceptor of acyl groups in cellular metabolism. The major solution conformation of carnitine about C3- C4 contains the gauche relationship between the trimethylammonium and hydroxy groups, while two of the three low-energy, staggered conformations about C2-C3 are significantly populated. For studies of carnitine's protein binding sites, we designed conformationally ...