Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2009-4-17
pubmed:databankReference
pubmed:abstractText
Lectin AAL (Agrocybe aegerita lectin) from the edible mushroom A. aegerita is an antitumor protein that exerts its tumor-suppressing function via apoptosis-inducing activity in cancer cells. The crystal structures of ligand-free AAL and its complex with lactose have been determined. The AAL structure shows a dimeric organization, and each protomer adopts a prototype galectin fold. To identify the structural determinants for antitumor effects arising from the apoptosis-inducing activity of AAL, 11 mutants were prepared and subjected to comprehensive investigations covering oligomerization detection, carbohydrate binding test, apoptosis-inducing activity assay, and X-ray crystallographic analysis. The results show that dimerization of AAL is a prerequisite for its tumor cell apoptosis-inducing activity, and both galactose and glucose are basic moieties of functional carbohydrate ligands for lectin bioactivity. Furthermore, we have identified a hydrophobic pocket that is essential for the protein's apoptosis-inducing activity but independent of its carbohydrate binding and dimer formation. This hydrophobic pocket comprises a hydrophobic cluster including residues Leu33, Leu35, Phe93, and Ile144, and is involved in AAL's function mechanism as an integrated structural motif. Single mutants such as F93G or I144G do not disrupt carbohydrate binding and homodimerization capabilities, but abolish the bioactivity of the protein. These findings reveal the structural basis for the antitumor property of AAL, which may lead to de novo designs of antitumor drugs based on AAL as a prototype model.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
1089-8638
pubmed:author
pubmed:issnType
Electronic
pubmed:day
3
pubmed:volume
387
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
694-705
pubmed:meshHeading
pubmed-meshheading:19361423-Agrocybe, pubmed-meshheading:19361423-Amino Acid Sequence, pubmed-meshheading:19361423-Antineoplastic Agents, pubmed-meshheading:19361423-Apoptosis, pubmed-meshheading:19361423-Binding Sites, pubmed-meshheading:19361423-Carbohydrates, pubmed-meshheading:19361423-Cell Line, Tumor, pubmed-meshheading:19361423-Crystallography, X-Ray, pubmed-meshheading:19361423-Dimerization, pubmed-meshheading:19361423-Fungal Proteins, pubmed-meshheading:19361423-Humans, pubmed-meshheading:19361423-Lectins, pubmed-meshheading:19361423-Models, Molecular, pubmed-meshheading:19361423-Molecular Sequence Data, pubmed-meshheading:19361423-Mutagenesis, Site-Directed, pubmed-meshheading:19361423-Protein Folding, pubmed-meshheading:19361423-Protein Structure, Quaternary, pubmed-meshheading:19361423-Sequence Alignment
pubmed:year
2009
pubmed:articleTitle
Structural basis for the tumor cell apoptosis-inducing activity of an antitumor lectin from the edible mushroom Agrocybe aegerita.
pubmed:affiliation
National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Chaoyang District, Beijing, PR China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't