Linked Life Data

7803399

Source:http://linkedlifedata.com/resource/pubmed/id/7803399

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
51
pubmed:dateCreated
1995-1-27
pubmed:abstractText
Botulinum neurotoxin serotype B (BoNT/B) and tetanus toxin (TeTx) block neuroexocytosis through selective endoproteolysis of vesicle-associated membrane protein (VAMP). The enzymological properties of both toxins were compared for the first time in their cleavage of VAMP and various sized fragments using a sensitive chromatographic assay. The optimal substrate sizes for the zinc-dependent protease activities of the light chains of TeTx and BoNT/B were established using synthetic peptides corresponding to the hydrophilic core of VAMP (30-62 amino acids in length). TeTx was found to selectively cleave the largest peptide at a single site, Gln76-Phe77. It exhibited the most demanding specificity, requiring the entire hydrophilic domain (a 62-mer) for notable hydrolysis, whereas BoNT/B efficiently cleaved the much smaller 40-mer. Thus, an unusually long N-terminal sequence of 44 amino acids upstream of the scissile bond is required for the selective hydrolysis of VAMP by TeTx. Using the largest peptide, BoNT/B and TeTx exhibited approximately 50% and 35%, respectively, of the activities shown toward intact VAMP, detergent solubilized from synaptic vesicles. Given the large size of the smallest substrates, it is possible that these neurotoxins recognize and require a three-dimensional structure. Although both toxins were inactivated by divalent metal chelators, neither was antagonized by phosphoramidon or ASQFETS (a substrate-related peptide that spans the cleavage site), and TeTx was only feebly inhibited by captopril; also, they were distinguishable in their relative activities at different pHs, temperatures, and ionic strengths. These collective findings are important in the design of effective inhibitors for both toxins, as well as in raising the possibility that TeTx and BoNT/B interact somewhat differently with VAMP.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
15365-74
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:7803399-Amino Acid Sequence, pubmed-meshheading:7803399-Botulinum Toxins, pubmed-meshheading:7803399-Captopril, pubmed-meshheading:7803399-Chelating Agents, pubmed-meshheading:7803399-Dithiothreitol, pubmed-meshheading:7803399-Endopeptidases, pubmed-meshheading:7803399-Humans, pubmed-meshheading:7803399-Hydrogen-Ion Concentration, pubmed-meshheading:7803399-Kinetics, pubmed-meshheading:7803399-Membrane Proteins, pubmed-meshheading:7803399-Molecular Sequence Data, pubmed-meshheading:7803399-Nerve Tissue Proteins, pubmed-meshheading:7803399-Osmolar Concentration, pubmed-meshheading:7803399-Peptide Mapping, pubmed-meshheading:7803399-Peptides, pubmed-meshheading:7803399-R-SNARE Proteins, pubmed-meshheading:7803399-Substrate Specificity, pubmed-meshheading:7803399-Temperature, pubmed-meshheading:7803399-Tetanus Toxin
pubmed:year
1994
pubmed:articleTitle
Differences in the protease activities of tetanus and botulinum B toxins revealed by the cleavage of vesicle-associated membrane protein and various sized fragments.
pubmed:affiliation
Department of Biochemistry, Imperial College, London, U.K.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't