Stereospecificity of mushroom tyrosinase immobilized on a chiral and a nonchiral support

Mushroom tyrosinase was immobilized from an extract onto glass beads covered with the cross-linked totally cinnamoylated derivates of d-sorbitol (sorbitol cinnamate) and glycerine (glycerine cinnamate). The enzyme was immobilized onto the support by direct adsorption, and the quantity of immobilized tyrosinase was higher for sorbitol cinnamate, the support with the higher number of esterified hydroxyls per unit of monosacharide, than for glycerine cinnamate. The results obtained from the stereospecificity study of the monophenolase and diphenolase activity of immobilized mushroom tyrosinase are reported. The enantiomers l-tyrosine, dl-tyrosine, d-tyrosine, l-dopa, dl-dopa, d-dopa, l-α-methyldopa, dl-α-methyldopa, l-isoprenaline, dl-isoprenaline, l-adrenaline, dl-adrenaline, l-noradrenaline, and d-noradrenaline were assayed with tyrosinase immobilized on a chiral support (sorbitol cinnamate), whereas l-tyrosine, dl-tyrosine, d-tyrosine, l-dopa, dl-dopa, d-dopa, l-α-methyldopa, and dl-α-methyldopa were assa...