Quaternary structure of mushroom tyrosinase

Influence of Sodium Periodate and Tyrosinase on Binding of Alginate to Adlayers of Mytilus edulis Foot Protein 1

“…This suggests that the moderate reduction in ε-amino groups in Mefp-1 adlayers by exposure to mushroom tyrosinase is due to obstruction of alginate binding sites on Mefp-1 (some form of steric hindrance), rather than the result of a reaction with quinones. Results of Table 1, row 6 indicate that binding of mushroom tyrosinase to Mefp-1 adlayers contributes only a slight portion of ε-amino groups to the composite adlayer and this is consistent with the relatively low lysine content of mushroom tyrosinase (4.9%) (21).…”

“…Adlayers of mushroom tyrosinase have almost negligable ε-amino groups accessible for alginate binding as indicated by the data for adsorption of alginate to adlayers of mushroom tyrosinase on clean Ge at 0.5 mg/ ml bulk concentration (mt(0.5)/Ge). This is not surprising since the lysine content of mushroom tyrosinase is only 4.9% (21). Thus, the appearance of alg II upon exposure of composite Mefp-1-mushroom tyrosinase adlayers to alginate is due to binding of alginate to the ε-amino groups of Mefp-1.…”

Production, Purification and Properties of Extracellular Laccase of Agaricus bisporus

“…bisporus laccase may also be due to differences in the length of associated glycan chains, and the subunit structure may well be of a simple dimeric form as suggested recently for the tyrosinase of A . bisporus (Strothkamp et al, 1976).…”

Potent inhibitory effects of benzyl and p-xylidine-bis dithiocarbamate sodium salts on activities of mushroom tyrosinase

“…In addition, defects in tyrosinase may cause some diseases such as albinism and vitiligo 15,16 . Tyrosinase from A. bisporus was reported to be a hetero tetramer comprising two heavy (H) and light (L) chains with a molecular mass of 120 kDa 17 . The enzyme tyrosinase has three domains, of which the central domain contains two Cu binding sites, called CuA and CuB.…”

“…Each atom of the binuclear copper cluster is ligated to three histidine residues 18 . This pair of copper ions in the active site of the enzyme tyrosinase interacts with both molecular oxygen and its phenolic substrate 17 . Active sites of tyrosinase have three different states of binuclear copper structure ( Figure 1): met-tyrosinase (E met ), deoxy-tyrosinase (E deoxy ), and oxy-tyrosinase (E oxy ) 19 .…”