OPIOID-PEPTIDES DETERMINATION BY TYROSINASE-MODIFIED OXYGEN-ELECTRODE

Opioid peptides morphiceplin (Tyr-Pro-Phe-Pro-NH2), [D-Ala(2), D-Leu(5 )]-enkephalin (Tyr-D-Ala-Gly-Phe-D-Leu, DADLE) and [D-Thr(2)]-Leu-enke phalin-Thr (Tyr-D-Thr-Gly-Phe-Leu-Thr, DTLET) containing tyrosine has been studied in the reaction with mushroom tyrosinase immobilized on C lark-type oxygen electrode. A 4-6-times higher response is observed fo r tyrosine compared to peptides. The detection Limit of the tyrosinase -modified electrode for DADLE, morphiceptin and DTLET was 6 mu M, 9 mu M and 16 mu M, respectively.