Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1998-3-18
pubmed:abstractText
Cultivated varieties of the common bean (Phaseolus vulgaris L.) contain an alpha-amylase inhibitor (alpha AI-1) that inhibits porcine pancreatic alpha-amylase (PPA; EC 3.2.1.1) and the amylases of certain seed weevils, but not that of the Mexican bean weevil, Zabrotes subfasciatus. A variant of alpha AI-1, called alpha AI-2, is found in certain arcelin-containing wild accessions of the common bean. The variant alpha AI-2 inhibits Z. subfasciatus alpha-amylase (ZSA), but not PPA. We purified alpha AI-2 and studied its interaction with ZSA. The formation of the alpha AI-2-ZSA complex is time-dependent and occurs maximally at pH 5.0 or below. When a previously isolated cDNA assumed to encode alpha AI-2 was expressed in transgenic tobacco seeds, the seeds contained inhibitory activity toward ZSA but not toward PPA, confirming that the cDNA encodes alpha AI-2. The inhibitors alpha AI-1 and alpha AI-2 share 78% sequence identity at the amino acid level and they differ in an important region that is part of the site where the enzyme binds the inhibitor. The swap of a tripeptide in this region was not sufficient to change the specificity of the two inhibitors towards their respective enzymes. The three-dimensional structure of the alpha AI-1/PPA complex has just been solved and we recently obtained the derived amino acid sequence of ZSA. This additional information allows us to discuss the results described here in the framework of the amino acid residues of both proteins involved in the formation of the enzyme-inhibitor complex and to pinpoint the amino acids responsible for the specificity of the interaction.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
B
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0032-0935
pubmed:author
pubmed:issnType
Print
pubmed:volume
203
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
295-303
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:9431678-Amino Acid Sequence, pubmed-meshheading:9431678-Animals, pubmed-meshheading:9431678-Beetles, pubmed-meshheading:9431678-Enzyme Inhibitors, pubmed-meshheading:9431678-Fabaceae, pubmed-meshheading:9431678-Molecular Sequence Data, pubmed-meshheading:9431678-Pancreas, pubmed-meshheading:9431678-Plant Proteins, pubmed-meshheading:9431678-Plants, Genetically Modified, pubmed-meshheading:9431678-Plants, Medicinal, pubmed-meshheading:9431678-Plants, Toxic, pubmed-meshheading:9431678-Recombinant Fusion Proteins, pubmed-meshheading:9431678-Seeds, pubmed-meshheading:9431678-Sequence Alignment, pubmed-meshheading:9431678-Sequence Homology, Amino Acid, pubmed-meshheading:9431678-Species Specificity, pubmed-meshheading:9431678-Swine, pubmed-meshheading:9431678-Tobacco, pubmed-meshheading:9431678-Trypsin Inhibitors, pubmed-meshheading:9431678-alpha-Amylases
pubmed:year
1997
pubmed:articleTitle
Molecular characterization of a bean alpha-amylase inhibitor that inhibits the alpha-amylase of the mexican bean weevil Zabrotes subfasciatus.
pubmed:affiliation
Department of Biology, University of California, San Diego, La Jolla 92093-0116 USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't