A highly magnetically aligned metallothionein (MT) containing manganese (Mn) and cadmium (Cd) has been synthesized. The metallotionein has a formula of Mn.sub.x Cd.sub.7-x MT with x being in the range of 1 to 6. Its size and biological functions are similar as those of the native metallothionein as tested by dynamic light scattering, UV, and CD spectroscopic experimental methods. Its maximum magnetic moment per formula unit, in saturation field, is estimated to be 19.46 .mu..sub.B, and persists from 277 to 330 K.