Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1975-12-23
pubmed:abstractText
The amino acid composition of the isolated A- and B-chains of the toxic lectins abrin and ricin was determined and compared. Even though the two toxins originate from widely different plants, statistical analysis of the amino acid content indicates extensive homologies in the amino acid sequence of the 4 chains. The intact lectins contain no free SH-groups whereas the isolated A- and B-chains contain close to one free SH-group each. The results indicate that in both toxins the A- and B-chains are connected by a single S-S bond. The B-chains of abrin and ricin contain similar amounts of mannose and glucosamine. The A-chain of ricin also contains some carbohydrate, whereas the A-chain of abrin appears not to be a glycoprotein. The non-toxic abrus and ricinus agglutinins contain more carbohydrate than abrin and ricin. The isoelectric points of the different lectin preparations were measured by isoelectrofocusing. The intact lectins are much more resistant to heat, freezing and chemical treatments than the isolated A- and B-chains. The intact lectins are also very resistant to treatment with proteolytic enzymes, whereas the isolated chains are easily digested. Evidence indicating that the toxins and their chains undergo extensive conformational changes upon reduction of the S-S bond is discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
9
pubmed:volume
405
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-10
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
Studies on the structure and properties of the lectins from Abrus precatorius and Ricinus communis.
pubmed:publicationType
Journal Article, Comparative Study