Purification and characterization of a lectin from seeds of Vatairea macrocarpa Duke.
A lectin from Vatairea macrocarpa Duke seeds (VML) was isolated using affinity chromatography on a guar gum column. The lectin, a glycoprotein without erythrocyte specificity, displays specificity to galactose and some derivatives. On SDS-polyacrylamide gels, V. macrocarpa seed lectin is composed of two major high-Mr bands of 34 and 32 kDa and two minor low-Mr bands of 22 and 13 kDa. N-Terminal sequencing showed that the 34, 32, and 13 kDa products possess identical N-terminal sequence, which display best similarity with the N-terminal portion of Robinia pseudoacacia lectins (RPL). On the other hand, the N-terminal sequence of the 22 kDa band can be aligned with an internal sequence of RPL starting at residue 149 of the cDNA-derived sequence. These data indicate that, like other leguminous lectins, VML is made up of a mixture of one-chain 30-35 kDa glycoforms and of 22 and 13 kDa endogenous C- and N-terminal fragments. Size-exclusion chromatography indicated that, at neutral pH, VML is predominantly a dimeric (70 kDa) protein, although tetramers (115 kDa) and larger aggregates (300 kDa) were also present.
Cavada
B S
BS
Depto de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Fortaleza-Ce, Brazil. bscavada@ufc.br
Santos
C F
CF
Grangeiro
T B
TB
Nunes
E P
EP
Sales
P V
PV
Ramos
R L
RL
De Sousa
F A
FA
Crisostomo
C V
CV
Calvete
J J
JJ
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D007887:Fabaceae / Q000737:chemistry*; D005690:Galactose / Q000378:metabolism; D006386:Hemagglutination Tests; D006801:Humans; D066298:In Vitro Techniques; D037102:Lectins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D037121:Plant Lectins; D010946:Plants, Medicinal
D000596:Amino Acids; D002241:Carbohydrates; D037102:Lectins; D037121:Plant Lectins; D005690:Galactose