PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 2477025

Patch-clamp capacitance measurements: a tool for investigating the second messengers regulating exocytosis.

M Lindau
View original source ↗Export metadata ↓

Abstract

The source did not provide an abstract. Follow the original record for more information.

Explore related subjects

Adenosine Diphosphate RiboseAnimalsCalciumCell MembraneExocytosisFluorescent DyesGTP-Binding ProteinsGuanosine 5'-O-(3-Thiotriphosphate)Guanosine TriphosphateHeparinHistamine ReleaseImmunoglobulin MMast CellsPeritoneal CavityRatsReceptors, FcSecond Messenger SystemsThionucleotidesJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

M Lindau. 1989. Patch-clamp capacitance measurements: a tool for investigating the second messengers regulating exocytosis.. https://doi.org/10.1007/bf01674316

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Cytoprotective agent in Lactobacillus bulgaricus extracts.

Adenosine 5'-diphosphoribose (ADP-ribose) has been identified as a significant contributor to the anti-cytotoxic activity of Lactobacillus bulgaricus extracts. Although the biological activities associated with the administration of probiotic bacteria and components thereof are sometimes attributed to the peptidoglycans that comprise a substantial portion of the Gram-positive bacterial cell wall, we found that the beta-nicotine adenine dinucleotide (NAD) hydrolysis product ADP-ribose was a significant contributor to the observed anti-cytotoxicity in our L. bulgaricus extracts. The ADP-ribose was isolated, identified, and quantitated by high performance liquid chromatography (HPLC) and by nuclear magnetic resonance (NMR) spectroscopy. ADP-ribose levels as low as 5 mg/L exhibited a measurable inhibition of tumor necrosis factor alpha (TNF-alpha) mediated cytotoxicity in an in vitro cell assay, whereas the ADP-ribose content of the L. bulgaricus extracts often exceeded 5 mg/g dry weight.

Adenosine Diphosphate Ribose↗
PubMed2006

Human alpha-defensins neutralize toxins of the mono-ADP-ribosyltransferase family.

Various bacterial pathogens secrete toxins, which are not only responsible for fatal pathogenesis of disease, but also facilitate evasion of host defences. One of the best-known bacterial toxin groups is the mono-ADP-ribosyltransferase family. In the present study, we demonstrate that human neutrophil alpha-defensins are potent inhibitors of the bacterial enzymes, particularly against DT (diphtheria toxin) and ETA (Pseudomonas exotoxin A). HNP1 (human neutrophil protein 1) inhibited DT- or ETA-mediated ADP-ribosylation of eEF2 (eukaryotic elongation factor 2) and protected HeLa cells against DT- or ETA-induced cell death. Kinetic analysis revealed that inhibition of DT and ETA by HNP1 was competitive with respect to eEF2 and uncompetitive against NAD+ substrates. Our results reveal that toxin neutralization represents a novel biological function of HNPs in host defence.

Adenosine Diphosphate Ribose↗
PubMed2006

Crystal structures of human NUDT5 reveal insights into the structural basis of the substrate specificity.

Human NUDT5 (hNUDT5) is an ADP-ribose pyrophosphatase (ADPRase) belonging to the Nudix hydrolase superfamily. It presumably plays important roles in controlling the intracellular level of ADP-ribose (ADPR) to prevent non-enzymatic ADP-ribosylation by hydrolyzing ADPR to AMP and ribose 5'-phosphate. We report here the crystal structures of hNUDT5 in apo form, in complex with ADPR, and in complex with AMP with bound Mg2+. hNUDT5 forms a homodimer with substantial domain swapping and assumes a structure more similar to Escherichia coli ADPRase ORF209 than human ADPRase NUDT9. The adenine moiety of the substrates is specifically recognized by the enzyme via hydrogen-bonding interactions between N1 and N6 of the base and Glu47 of one subunit, and between N7 of the base and Arg51 of the other subunit, providing the molecular basis for the high selectivity of hNUDT5 for ADP-sugars over other sugar nucleotides. Structural comparisons with E. coli ADPRase ORF209 and ADPXase ORF186 indicate that the existence of an aromatic residue on loop L8 in ORF186 seems to be positively correlated with its enzymatic activity on APnA, whereas hNUDT5 and ORF209 contain no such residue and thus have low or no activities on APnA.

Adenosine Diphosphate Ribose↗