Two conserved histidine residues are located near the mid-point of the conduction channel of ammonium transport proteins. The role of these histidines in ammonia and methylamine transport was evaluated by using a combination of in vivo studies, molecular dynamics (MD) simulation, and potential of mean force (PMF) calculations. Our in vivo results showed that a single change of either of the con...

Radioiodinated transforming growth factor-,61 (TGF-,i1) bound to the plasma proteinase inhibitor, a2-macroglobulin (a2M), as determined by chromatography on Superose-6 and native polyacrylamide gel electrophoresis. When a2M conformational change was induced with methylamine, 1"I-TGF-jfl binding significantly increased. Intravenously injected 125I_ TGF-il cleared from the circulation of mice rap...

Methyloversatilis universalis FAM5 utilizes single carbon compounds such as methanol or methylamine as a sole source of carbon and energy. Expression profiling reveals distinct sets of genes altered during growth on methylamine vs methanol. As expected, all genes for the N-methylglutamate pathway were induced during growth on methylamine. Among other functions responding to the aminated source ...

Ammonia is a very useful chemical ionization (CI) reagent gas for the qualitative analyses of compounds by positive ion gas chromatography-mass spectrometry (GCMS). The gas is readily available, inexpensive, and leaves no carbon contamination in the MS source. Compounds of interest to our laboratory typically yield abundant protonated or ammoniated species, which are indicative of a compound's ...

Incubation of purified human beta 2-microglobulin (B2-m) with tissue transglutaminase (Tgase) resulted in the formation of high molecular weight polymers revealed by sodium dodecyl sulfate polyacrylamide gel electrophoresis. In the presence of 30 mM [14C]methylamine, the polymer formation was prevented, but incorporation of methylamine into beta 2-m (equal to 1 methylamine per 1 molecule) could...

The mau gene cluster of Paracoccus denitrificans constitutes 11 genes (10 are located in the transcriptional order mauFBEDACJGMN; the 11th, mauR, is located upstream and divergently transcribed from these genes) that encode a functional methylamine-oxidizing electron transport branch. The mauR gene encodes a LysR-type transcriptional activator essential for induction of the mau operon. In this ...

Lung lamellar bodies, the storage organelles for lung surfactant phosphatidylcholine (PC), maintain an acidic pH that can be increased with weak bases. This study investigates the effect of a weak base, methylamine, on the pH in lamellar bodies and on the trafficking and packaging of newly synthesized PC in lamellar bodies. Methylamine increased the pH of isolated lung lamellar bodies and of la...

Dehydrogenases are interesting candidates for the development of electrochemical biosensors. Most dehydrogenases are characterised by a comparatively broad substrate spectrum, yet highly specific enzymes exist as well. A specific formaldehyde dehydrogenase has, e.g., been described for the organism Hyphomicrobium zavarzinii ZV580. Isolation of enzymes from their natural source instead of a reco...

Methylamine dehydrogenase from Paracoccus denitrificans was purified to homogeneity in two steps from the periplasmic fraction of methylamine-grown cells. The enzyme exhibited a pI value of 4.3 and was composed of two 46,700-dalton subunits and two 15,500-dalton subunits. Each small subunit possessed a covalently bound pyrrolo-quinoline quinone prosthetic group. The amino acid compositions of t...