Konrad Lerch

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Natural vanillin is of high interest in the flavor market. Microbial routes to vanillin have so far not been economical as the medium concentrations achieved have been well below 1 g l−1. We have now screened microbial isolates from nature and known strains for their ability to convert eugenol or ferulic acid into vanillin. Ferulic acid, in contrast to the(More)
A precursor form of Neurospora crassa tyrosinase has been identified by Western transfer from crude protein extracts and by immunoprecipitation of in vitro translated tyrosinase mRNA. The molecular weight of protyrosinase (75,000) exceeds that of mature tyrosinase (46,000) by about 50%. In order to deduce the primary structure and the nature of the(More)
Asp-208 of Streptomyces glaucescens tyrosinase (an invariant residue in the CuB-binding region of tyrosinases and haemocyanins) was conservatively substituted by glutamic acid. Although having little effect on spectroscopic or kinetic properties of the enzyme, the mutation greatly decreased the lability of Cu-bound O2. A rationalization for these results is(More)
The complete structures of the laccase genes isolated from two different Neurospora crassa wild-type strains are described. The genes were cloned by screening partial genomic DNA libraries with a nick-translated laccase-specified 1.36-kilobase SalI fragment (Germann, U. A., and Lerch, K. (1986) Proc. Natl. Acad. Sci. U.S.A. 83, 8854-8858) as a hybridization(More)
Tyrosinase is a copper containing monooxygenase catalyzing the formation of melanin pigments and other polyphenolic compounds from various phenols. This review deals with the recent progress on the molecular structure of the enzyme from Neurospora crassa and the unique features of the binuclear active site copper complex involved in the activation of(More)
The influence of copper on the cycloheximide-induced synthesis of the copper-containing enzymes tyrosinase and laccase in Neurospora crassa was studied by enzyme activity measurements and immunological means. The amount of active enzyme molecules is far higher when the culture medium is copper-supplemented before cycloheximide induction. The synthesis of(More)
The promoter region of the Neurospora crassa metallothionein gene contains no sequences which are similar to the mammalian or the yeast metal responsive elements (Münger, K., Germann, U. A., and Lerch, K. (1985) EMBO J. 4, 2665-2668). We therefore studied the regulation of expression of the N. crassa metallothionein gene in response to different metal ions(More)
Upon induction with various amine sources, two different amine oxidases are expressed in the filamentous fungus Aspergillus niger. The enzymes which can be separated by anion exchange chromatography exhibit a similar substrate specificity pattern. From cofactor and inhibitor analysis it was found that one amine oxidase is identical to the earlier reported(More)