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The consequences of deglycosylation of recombinant intra-melanosomal domain of human tyrosinase.

ABSTRACT: Tyrosinase, a melanosomal glycoenzyme, catalyzes initial steps of the melanin biosynthesis. While glycosylation was previously studied in vivo, we present three recombinant mutant variants of human tyrosinase, which were obtained using multiple site-directed mutagenesis, expressed in insect larvae, purified and characterized biochemically. The mutagenesis demonstrated the reduced protein expression and enzymatic activity due to possible loss of protein stability and protein degradation. However, the complete deglycosylation of asparagine residues in vitro, including the residue in position 371, interrupts tyrosinase function, which is consistent with a melanin loss in oculocutaneous albinism type 1 (OCA1) patients.

SUBMITTER: Dolinska MB

PROVIDER: S-EPMC6108172 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature

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The consequences of deglycosylation of recombinant intra-melanosomal domain of human tyrosinase.

Dolinska Monika B MB Sergeev Yuri V YV

Biological chemistry 20171201 1

Tyrosinase, a melanosomal glycoenzyme, catalyzes initial steps of the melanin biosynthesis. While glycosylation was previously studied in vivo, we present three recombinant mutant variants of human tyrosinase, which were obtained using multiple site-directed mutagenesis, expressed in insect larvae, purified and characterized biochemically. The mutagenesis demonstrated the reduced protein expression and enzymatic activity due to possible loss of protein stability and protein degradation. However, ...[more]

PMID: 28858842

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