TABLE 2.
Proteins, sugars, and enzymes used in competition assays for binding of citrus tristeza virus proteins with excised mouthparts of the brown citrus aphid, Toxoptera citricia
| Protein, sugar, or enzyme | Competitora | Characterization, activity, and/or affinity |
|---|---|---|
| Viral proteins | L1 | Protease |
| L2 | Protease | |
| P13 | Host range determinant | |
| P18 | Host range determinant | |
| P20 | Silencing suppressor | |
| P23 | Silencing suppressor | |
| P25 | Coat protein and silencing suppressor | |
| P27 | Minor coat protein | |
| P61 | Heat shock protein 90 h | |
| P65 | Heat shock protein 70 h | |
| Proteins | ConA | Lectin with affinity to carbohydrates with terminal mannose or glucose (αMan > αGlc > GlcNAc) |
| LCA | Lectin with affinity to branched mannose with fucose linked α(1,6) to the N-acetylglucosamine, (αMan > αGlc > GlcNAc) | |
| WGA | Lectin with affinity to N-linked oligosaccharides, [GlcNAc(β1,4GlcNAc) > βGlcNAc] | |
| PNA | Lectin with affinity to terminal β-galactose, (Galβ1,3GalNAc > α and βGal) | |
| BSA | Neutral protein (no sugar affinity) | |
| OV | Glycoprotein with affinity to lectins | |
| Sugars | d-Galactose | Reducing monosaccharide (Fisher projection) |
| d-Mannose | Reducing monosaccharide (Fisher projection) | |
| d-Glucose | Reducing monosaccharide (Fisher projection) | |
| Methyl α-d-galactopyranoside | Pyranose form of galactose (Haworth projection) | |
| Methyl α-d-mannopyranoside | Pyranose form of mannose (Haworth projection) | |
| Methyl α-d-glucopyranoside | Pyranose form of glucose (Haworth projection) | |
| N-Acetylglucosamine (GlcNAc) | Monomer of chitin (the insect cytoskeleton) | |
| Chitobiose (GlcNAc)2 | Dimer of N-acetylglucosamine | |
| Chitotriose (GlcNAc)3 | Trimer of N-acetylglucosamine | |
| Enzymes | Pronase E | Protease with activity against denatured and native proteins leading to complete or nearly complete digestion into individual amino acids |
| Protease K | Protease cleaves native proteins between amino acids X and Y (X ↓ Y), when X is an aliphatic, aromatic, or hydrophobic amino acid and Y is any amino acid | |
| Trypsin | Trypsin cleaves peptide chains mainly at the carboxyl side of the amino acids lysine or arginine, except when either is followed by proline | |
| Chitinase | Chitinase is an extracellular enzyme complex that degrades chitin into chitobioses |
a
ConA, concanavalin A; LCA, lens culinaris agglutinin; WGA, wheat germ agglutinin; PNA, peanut agglutinin; BSA, bovine serum albumin; OV, ovalbumin.