NANOBODY molecules are an innovative class of biotherapeutics based on heavy chain only VHH immunoglobulins. Much like canonical antibodies, they are prone to the formation of charge variants and other post-translational modifications, which can potentially impact their critical quality attributes. Therefore, establishing high-resolution product-specific methods, such as IEX chromatography, is essential for evaluating the purity of these molecules.
View Article and Find Full Text PDFShewanella oneidensis, a Gram-negative γ-proteobacterium with an extensive redox capacity, possesses four old yellow enzyme (OYE) homologs. Of these, Shewanella yellow enzyme 4 (SYE4) is implicated in resistance to oxidative stress. Here, we present a series of high-resolution crystal structures for SYE4 in the oxidized and reduced states, and in complex with phenolic ligands and the nitro-aromatic explosive picric acid.
View Article and Find Full Text PDFShewanella yellow enzyme (SYE-4), a novel recombinant enoate reductase, was screened against a variety of different substrates bearing an activated double bond, such as unsaturated cyclic ketones, diesters, and substituted imides. Dimethyl- and ethyl esters of 2-methylmaleic acid were selectively reduced to (R)-configured succinic acid derivatives and various N-substituted maleimides furnished the desired (R)-products in up to >99% enantiomeric excess. Naturally occurring (+)-carvone was selectively reduced to (-)-cis-dihydrocarvone and (-)-carvone was converted to the diastereomeric product, respectively.
View Article and Find Full Text PDFActa Crystallogr Sect F Struct Biol Cryst Commun
January 2010
Shewanella oneidensis is an environmentally versatile Gram-negative gamma-proteobacterium that is endowed with an unusually large proteome of redox proteins. Of the four old yellow enzyme (OYE) homologues found in S. oneidensis, SYE4 is the homologue most implicated in resistance to oxidative stress.
View Article and Find Full Text PDFMany studies have reported microorganisms as efficient biocatalysts for colour removal of dye-containing industrial wastewaters. We present the first comprehensive study to identify all molecular components involved in decolorization by bacterial cells. Mutants from the model organism Shewanella oneidensis MR-1, generated by random transposon and targeted insertional mutagenesis, were screened for defects in decolorization of an oxazine and diazo dye.
View Article and Find Full Text PDFThe Gram-negative bacterium Shewanella oneidensis MR-1 shows a remarkably versatile anaerobic respiratory metabolism. One of its hallmarks is its ability to grow and survive through the reduction of metallic compounds. Among other proteins, outer membrane decaheme cytochromes c OmcA and OmcB have been identified as key players in metal reduction.
View Article and Find Full Text PDFWe have recently reported that Shewanella oneidensis, a Gram-negative gamma-proteobacterium with a rich arsenal of redox proteins, possesses four old yellow enzyme (OYE) homologues. Here, we report a series of high resolution crystal structures for one of these OYEs, Shewanella yellow enzyme 1 (SYE1), in its oxidized form at 1.4A resolution, which binds a molecule of PEG 400 in the active site, and in its NADH-reduced and p-hydroxybenzaldehyde- and p-hydroxyacetophenone-bound forms at 1.
View Article and Find Full Text PDFShewanella oneidensis contains four genes that encode proteins that have high sequence identity with yeast OYE (Old Yellow Enzyme, an NADPH oxidoreductase), the well-studied archetype of the OYE protein family. The present paper describes the first comparative study of OYEs that are present in a single bacterial species, performed to gain insight into their biochemical properties and physiological importance. The four proteins [named SYE1-SYE4 (Shewanella Yellow Enzyme 1-4)] were expressed as glutathione S-transferase fusion proteins in Escherichia coli.
View Article and Find Full Text PDFShewanella oneidensis MR-1 is a free-living gram-negative gamma-proteobacterium that is able to use a large number of oxidizing molecules, including fumarate, nitrate, dimethyl sulfoxide, trimethylamine N-oxide, nitrite, and insoluble iron and manganese oxides, to drive anaerobic respiration. Here we show that S. oneidensis MR-1 is able to grow on vanadate as the sole electron acceptor.
View Article and Find Full Text PDFThe diheme cytochrome NapB constitutes the small subunit of a periplasmic nitrate reductase found in a wide variety of bacterial species, including pathogens. The NapB protein is essential in transferring electrons to the large catalytic subunit NapA, which subsequently reduces nitrate to nitrite. Here we present the crystal structure of a proteolyzed form of recombinant NapB from Haemophilus influenzae, which was determined by the multiple-wavelength anomalous dispersion (MAD) method at 1.
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