A novel platform for the production of nonhydroxylated gelatins based on the methylotrophic yeast Hansenula polymorpha.

The use of yeast as a host for heterologous expression of proteins that are normally derived from animal tissue is a promising way to ensure defined products that are devoid of potential harmful animal side products. Here we report on the production and secretion of a custom-designed gelatin, Hu3-His8, by the yeast Hansenula polymorpha. We observed that Hu3-His8 was poorly secreted by the heterologous Saccharomyces cerevisiae invertase secretion signal.

B-branch electron transfer in reaction centers of Rhodobacter sphaeroides assessed with site-directed mutagenesis.

Mutants of Rhodobacter (Rba.) sphaeroides are described which were designed to study electron transfer along the so-called B-branch of reaction center (RC) cofactors. Combining the mutation L(M214)H, which results in the incorporation of a bacteriochlorophyll, beta, for H(A) [Kirmaier et al.

A high-throughput screen for porphyrin metal chelatases: application to the directed evolution of ferrochelatases for metalloporphyrin biosynthesis.

Porphyrins are of particular interest in a variety of applications ranging from biocatalysis and chemical synthesis to biosensor and electronic technologies as well as cancer treatment. Recently, we have developed a versatile system for the high-level production of porphyrins in engineered E. coli cells with the aim of diversifying substitution patterns and accessing porphyrin systems not readily available through chemical synthesis.

High-level production of porphyrins in metabolically engineered Escherichia coli: systematic extension of a pathway assembled from overexpressed genes involved in heme biosynthesis.

Due to their spectroscopic properties porphyrins are of special interest for a variety of applications, ranging from drug development or targeting to material sciences and chemical and biological sensors. Since chemical syntheses are limited in terms of regio- and stereoselective functionalization of porphyrins, a biosynthetic approach with tailored enzyme catalysts offers a promising alternative. In this paper, we describe assembly of the entire heme biosynthetic pathway in a three-plasmid system and overexpression of the corresponding genes with Escherichia coli as a host.

Recent efforts in engineering microbial cells to produce new chemical compounds.

In the process of evolution, variation and combination of basic building blocks has led to an astonishing wealth of secondary metabolites. Recently, the same evolutionary tools have been used to create novel compounds that have not been found in nature.

High yield of B-branch electron transfer in a quadruple reaction center mutant of the photosynthetic bacterium Rhodobacter sphaeroides.

A new reaction center (RC) quadruple mutant, called LDHW, of Rhodobacter sphaeroides is described. This mutant was constructed to obtain a high yield of B-branch electron transfer and to study P(+)Q(B)(-) formation via the B-branch. The A-branch of the mutant RC contains two monomer bacteriochlorophylls, B(A) and beta, as a result of the H mutation L(M214)H.