Transient occurrence of an ebulin-related D-galactose-lectin in shoots of Sambucus ebulus L.
Young shoots of Sambucus ebulus L. contain a monomeric d-galactose binding lectin (SELlm), which disappears upon shoot development, and was previously undetected since it co-purifies with the non-toxic type 2 ribosome-inactivating protein ebulin l and the dimeric lectin SELld. Molecular cloning of cDNA coding for SELlm and mass spectrometry analysis revealed a protein with a molecular mass of 34,239 Da, which displays 80%, 77% and 45% of amino acid sequence identity with the ebulin l-B chain, SELld and ricin-B chain, respectively. Furthermore, the cloned precursor, with respect to the ebulin l precursor is truncated and contains the signal peptide, a piece of the A chain, a piece of the connecting peptide and the B chain. Further processing yields the lectin protein, which contains only the B chain. Despite the fact that SELlm displays the same d-galactose-binding sites than ricin, it was found that the lectin has different binding properties to D-galactose-containing matrix than ricin. Notably, and unlike ricin, the binding of SELlm and other Sambucus lectins to such matrix was maximum in range of 0-10 degrees C and abolished at 20 degrees C.
Citores
Lucía
L
Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Valladolid, E-47005 Valladolid, Spain.
Rojo
María A
MA
Jiménez
Pilar
P
Ferreras
José M
JM
Iglesias
Rosario
R
Aranguez
Isabel
I
Girbés
Tomás
T
D000595:Amino Acid Sequence; D002846:Chromatography, Affinity; D003198:Computer Simulation; D037161:Galectins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008957:Models, Genetic; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism; D037121:Plant Lectins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018520:Plant Shoots / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012276:Ricin / Q000378:metabolism; D027923:Sambucus / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D037161:Galectins; D037121:Plant Lectins; D012276:Ricin