Purification, Characterization, and Gene Cloning ofCeriporiopsissp. Strain MD-1 Peroxidases That Decolorize Human Hair Melanin

Abstract

Ceriporiopsis sp. strain MD-1, isolated from forest soil, produced several extracellular enzymes that decolorized human hair melanin. Among them, three enzymes (E1, E2-1, and E2-2) were purified to homogeneity and characterized. The enzymes required hydrogen peroxide in their enzyme reactions and, typical of other fungal peroxidases, oxidized various phenol compounds such as guaiacol, but not 3,4-dimethoxybenzyl alcohol. The spectra of the three enzymes showed an absorption maximum at 406 nm, indicating that they were heme proteins. However, the A 406 /A 280 values of the enzymes were below 0.4, which was lower than those of other peroxidases. E2-1 and E2-2 were similar to each other in their molecular and catalytic properties, and they possibly represent products of posttranslational modifications and/or allelic variants of the same gene, mdcA. The corresponding cDNA was cloned and sequenced; the deduced amino acid sequence showed high identities to the manganese peroxidases from other microorganisms. The specific activities and K m values of E2-1 and E2-2 for synthetic and human hair melanins were much higher than those of Phanerochaete chrysosporium manganese peroxidase and lignin peroxidase.

Synthesis and assembly of fungal melanin

“…For example, a partially purified lignin peroxidase from P. chrysosporium can degrade the synthetic substrate 2,2-azino-bis [3-ethylbenzthiazoline-6-sulfonic acid] (ABTS) in a hydrogen peroxide-dependent reaction (Woo et al 2004). Similarly, a peroxidase capable of bleaching human hair melanin is found in Ceriporiopsis culture supernatants (Nagasaki et al 2008). …”

Characterization and application of a novel class II thermophilic peroxidase from Myceliophthora thermophila in biosynthesis of polycatechol

“…Steady-state kinetic parameters for both ABTS and H 2 O 2 appear higher than those reported for known ligninolytic peroxidases from Basidiomycetous sources [5,50]. Moreover, the oxidation rate of ABTS follows a sigmoidal kinetic, allowing the calculation of two sets of kinetic parameters.…”

“…Thermophilic nature is a valuable trait for the industrial application of any biocatalyst, as greater stability and activity at elevated temperatures can be obtained, compared to their mesophilic counterparts. Up to date, the basidiomycete's ligninolytic peroxidases that have been cloned and characterized, exhibit mainly a mesophilic nature that is not applicable to bulk, commercial processes [5,46]. For example, a VP from B. adusta lost all activity after 20 min incubation at 65 • C [46].…”

“…Melanin-decolorizing peroxidases from Ceriporiopsis sp. were reported to retain more than 60% of their activity at 60 • C, but the assay was restricted to 10-min incubations [5]. To overcome thermostability issues, laborious and time-consuming work is needed, such as directed evolution [7] or immobilization approaches [54].…”

“…They have been widely studied in the past 20 years, mainly due to their outstanding biotechnological potential. Their widespread presence is well documented while there are numerous studies reporting cloning and heterologous expression [2][3][4][5][6], or even directed evolution approaches [7] for the The various applications of peroxidases include the production of novel biomaterials, such as redox polymers. Redox polymers are used in numerous industrial fields, such as electrical conductors, batteries, electrode coatings for sensors, antioxidants and corrosion inhibitors [10].…”