Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
30
pubmed:dateCreated
2004-7-27
pubmed:abstractText
Lysenin is a sphingomyelin (SM)-specific toxin isolated from the coelomic fluid of the earthworm Eisenia foetida. Lysenin comprises a family of proteins together with lysenin-related protein 1 (LRP-1, lysenin 2) and LRP-2 (lysenin 3). In the present study, we characterized LRP-1 and LRP-2 together with lysenin using maltose-binding-protein-tagged recombinant proteins. LRP-2 specifically bound SM and induced hemolysis like lysenin. In contrast the binding and hemolytic activities of LRP-1 were 10 times less than those of lysenin and LRP-2. Lysenin and LRP-2 share 30 common sites of aromatic amino acids. Among them, only one position, phenylalanine 210, is substituted for isoleucine in LRP-1. The activity of LRP-1 was dramatically increased by introducing a single amino acid substitution of isoleucine 210 to phenylalanine, suggesting the importance of this aromatic amino acid in biological activities of lysenin and LRPs. The importance of aromatic amino acids was further indicated by a systematic tryptophan to alanine mutation of lysenin. Lysenin contains six tryptophan residues of which five are conserved in LRP-1 and -2. We showed that the conserved tryptophans but not the nonconserved one were required both in the recognition of SM and in the hemolytic activity of lysenin. Our results suggest the importance of tryptophan in the toxin function likely due to a direct recognition of SM or in maintaining the protein structure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9766-73
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed-meshheading:15274631-Amino Acid Sequence, pubmed-meshheading:15274631-Amino Acid Substitution, pubmed-meshheading:15274631-Animals, pubmed-meshheading:15274631-Carrier Proteins, pubmed-meshheading:15274631-Cell Line, Tumor, pubmed-meshheading:15274631-Cells, Cultured, pubmed-meshheading:15274631-Cytotoxins, pubmed-meshheading:15274631-Hemolysis, pubmed-meshheading:15274631-Humans, pubmed-meshheading:15274631-Isoleucine, pubmed-meshheading:15274631-Maltose-Binding Proteins, pubmed-meshheading:15274631-Mice, pubmed-meshheading:15274631-Molecular Sequence Data, pubmed-meshheading:15274631-Oligochaeta, pubmed-meshheading:15274631-Phenylalanine, pubmed-meshheading:15274631-Protein Binding, pubmed-meshheading:15274631-Proteins, pubmed-meshheading:15274631-Recombinant Proteins, pubmed-meshheading:15274631-Sphingomyelins, pubmed-meshheading:15274631-Structural Homology, Protein, pubmed-meshheading:15274631-Toxins, Biological, pubmed-meshheading:15274631-Tryptophan
pubmed:year
2004
pubmed:articleTitle
Recognition of sphingomyelin by lysenin and lysenin-related proteins.
pubmed:affiliation
RIKEN, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't