- ApplicationsConjugation, Puri
WGA Lectin validated data
|Full Name||Wheat Germ agglutinin, Triticum vulgaris|
|Synonyms||Wheat Germ agglutinin, Triticum vulgaris, Wheat germ agglutinin lectin, Wheat germ agglutinin, Triticum vulgaris, GlcNAc lectin, WGA, WGA Lectin, Triticum vulgaris lectin|
|Product Description||Triticum vulgaris lectin against N-acetyl glucosamine|
|Specificity||N-acetyl glucosamine (GlcNAc)|
|Background||Wheat germ agglutinin (WGA) (MW 36 kDa) is a dimeric, carbohydrate-free protein composed of two identical subunits. The amino acid sequence provides a figure of 21,600, based on 171 amino acids per polypeptide chain. The protein dissociates into monomers in acidic media, pK of the reaction 4. The receptor sugar for WGA is N-acetyl glucosamine (GlcNAc), GlcNacβ14GlcNAc. These structures are present in many serum and membrane glycoproteins, bacterial cell wall peptidoglycans, chitin, cartilage glycosaminogyycons and glycolipids. Native WGA also react with glycoproteins with sialic acid residue. This lectin is useful for the purification of insulin receptors, serum proteins and neuronal tracing. The carbohydrate-binding specificity of WGA has been studied by variety of techniques, such as hapten inhibition of hemagglutination and specific precipitation of glycoconjugate, changes in fluorescence of the lectin (intrinsic) or of chromatogenic ligands (extrinsic), equilibrium dialysis, NMR and x-ray diffraction. Inhibiting/Eluting sugars: 500 mM GlcNAc, dimer, trimmer or 100 mM acetic acid.Carbohydrate-Binding Specificity of WGA: Pentaacetylchitopentaose >Tetraacetylchitotetraose > triacetylchitotriose > Diacetylchitobiose > GlcNAc|
|Target||N-acetyl glucosamine (GlcNAc)|
|Application Note||Conjugation to Sepharose 4B (solid phase columns) to purify serum glycoproteins, membrane proteins and insulin receptors. For conjugation azide should be removed. Dilute in buffer containing 0.1 mM calcium chloride. The optimum dilution should be determined by the individual lab.|
|Storage Buffer||10 mM phosphate, 150 mM NaCl, pH 7.6, 0.1 mM Calcium chloride and 0.05% sodium azide|
|Storage Instruction||Store at 2-8°C.|
|Notes||For in vitro research use only. Not intended for any diagnostic or therapeutic purpose.|
Why is the observed Western Blot band size different from predicted size?
The predicted M.W. is based on protein sequence analysis; however, some factors might lead to an observed band size that is different from the predicted size. The reasons might include:
1.Post-translational modification (PTM):
a. Some post-translational modifications might lead to increased protein size, including
phosphorylation, acetylation, methylation, glycosylation, sumoylation, ubiquitination,
b. Some post-translational modifications might lead to decreased protein size including
phosphatidylethanolamine conjunction (e.g. LC3-II)
c. Some proteins may be cleaved to form an active or mature form; this process will
lead to a decreased protein size (e.g. Notch activation, Caspase activation, etc.)
d. Some websites provide useful PTM information
iv.CBS data sets http://www.cbs.dtu.dk/databases/
v.CBS prediction Servers http://www.cbs.dtu.dk/services/
2.mRNA splice variants (Isoforms):
Through alternative splicing, one gene can generate different proteins with different M.W. Regulation of alternative splicing depends upon cell type, conditions, etc.
Some proteins could form dimers or multimers, increasing the M.W. This phenomenon usually can be found in reducing gel condition; however, strong interactions may still be seen with higher molecular weight proteins even in denaturing gel.
The observed size could also potentially be influenced by the protein charge
Different species likely have different protein sequence and PTM, which can lead to a different protein M.W.