Towards synthetic catechol rich protein analogues through tyrosinase catalyzed activation of a tyrosine dipeptide in continuous mode

We present a perspective towards a green synthesis route for synthetic, catechol rich protein analogues (TCC). The method relies on the oxidation of a tyrosine dipeptide in continuous mode by the immobilized tyrosinase SinATyr followed by Michael addition of a dithiol. For the dipeptide substrate a kcat value of 0.16 s−1 and a Km value of 1.6 mM were determined meaning that its conversion is slower and the affinity towards the active center of the enzyme is lower compared to the standard substrate l-tyrosine (kcat = 5.6 s−1; Km = 0.24 mM). For the continuous operation mode SinATyr is immobilized on polyelectrolyte decorated silica microparticles with a k value of 0.11 s−1 (at 1 mM dipeptide substrate) after immobilization and finally experimental proof is given that the converted dipeptide in contact with the dithiol yields the desired TCC structures.