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Crystallization and preliminary X‐ray crystallographic analysis of polyphenol oxidase from Juglans regia ( jr PPO1)
Author(s) -
Zekiri Florime,
Bijelic Aleksandar,
Molitor Christian,
Rompel Annette
Publication year - 2014
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.572
H-Index - 37
ISSN - 2053-230X
DOI - 10.1107/s2053230x1400884x
Subject(s) - juglans , polyphenol oxidase , tyrosinase , chemistry , hydroxylation , crystallization , polyethylene glycol , enzyme , catechol oxidase , stereochemistry , crystallography , organic chemistry , biochemistry , peroxidase
Tyrosinase is a type 3 copper enzyme that catalyzes the ortho ‐hydroxylation of monophenols to diphenols as well as their subsequent oxidation to quinones, which are precursors for the biosynthesis of melanins. The first plant tyrosinase from walnut leaves ( Juglans regia ) was purified to homogeneity and crystallized. During the purification, two forms of the enzyme differing only in their C‐termini [ jr PPO1(Asp 101 –Pro 444 ) and jrPPO1 (Asp 101 –Arg 445 )] were obtained. The most abundant form jr PPO1(Asp 101 –Arg 445 ), as described in Zekiri et al. [ Phytochemistry (2014), 101 , 5–15], was crystallized, resulting in crystals that belonged to space group C 121, with unit‐cell parameters a = 115.56, b = 91.90, c = 86.87 Å, α = 90, β = 130.186, γ = 90°, and diffracted to 2.39 Å resolution. Crystals were only obtained from solutions containing at least 30% polyethylene glycol 5000 monomethyl ether in a close‐to‐neutral pH range.