Chemical characterization of the lectin from Amaranthus leucocarpus syn. hypocondriacus by 2-D proteome analysis.
In this work, we characterized chemically the N-acetyl-D-galactosamine specific lectin from Amaranthus leucocarpus syn hypocondriacus lectin (ALL). It is a dimeric glycoprotein composed by three isoforms with pl at 4.8, 4.9, and 5.2. Circular dichroism analysis indicated that the secondary structure of ALL contains 45% of \bibeta-sheet and 5% of \bialpha-helix. Amino acid sequence of the purified lectin and its isoforms was determined from peptides obtained after trypsin digestion by MALDI-TOF (Matrix assisted laser desorption ionization-time of flight). The tryptic peptides prepared from the purified lectin and the three isoforms showed different degrees (80 to 83%) of identity with the amino acid sequence belonging to a previously described high nutritional value protein from A. hypocondriacus not shown at the time to be a lectin. Furthermore, analysis of tryptic peptides obtained from ALL previously treated with peptide N-glycosidase, revealed a 93% identity with the aforementioned protein. Presence of N-glycosidically linked glycans of the oligomannosidic type and, in minor proportion, of the N-acetyllactosaminic type glycans was determined by affinity chromatography on immobilized Con A.
Hernández
P
P
Departamento de Bioquímica, Instituto Nacional de Enfermedades Respiratorias, Tlalpan D.F., 14080, México.
Debray
H
H
Jaekel
H
H
Garfias
Y
Y
Jiménez Md
M del C
Mdel C
Martínez-Cairo
S
S
Zenteno
E
E
D027721:Amaranthus / Q000737:chemistry*; D000595:Amino Acid Sequence; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry; D002846:Chromatography, Affinity; D002942:Circular Dichroism; D015180:Electrophoresis, Gel, Two-Dimensional; D006023:Glycoproteins / Q000737:chemistry*; D006386:Hemagglutination Tests; D037102:Lectins / Q000737:chemistry*; D008969:Molecular Sequence Data; D037121:Plant Lectins; D020033:Protein Isoforms / Q000737:chemistry; D020543:Proteome; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
C121359:Amaranthus leucocarpus lectin; D002241:Carbohydrates; D006023:Glycoproteins; D037102:Lectins; D037121:Plant Lectins; D020033:Protein Isoforms; D020543:Proteome