Database Searches with the Search Algorithms
. | . | Number of matchesin databases . | . | . | . | |||
|---|---|---|---|---|---|---|---|---|
| Search algorithm . | . | Gluten . | Hordein . | Secalin . | Avenin . | |||
| Algorithm 1 | Q4XPQ7X(YFWIL) | 52 | 48 | 8 | - | |||
| Algorithm 1 – Q4 | XXPQ7X(YFWIL) | 334 | 91 | 14 | 6 | |||
| Algorithm 1 – Q7 | Q4XPXX(YFWIL) | 286 | 142 | 60 | 11 | |||
| Algorithm 2 | Q4XPQ7XP(YFWIL) | 46 | 60 | 33 | - | |||
| Algorithm 2 – Q4a | XXPQ7XP(YFWIL) | 262 | 196 | 89 | - | |||
| Algorithm 2 – Q7 | Q4XPXXP(YFWIL) | 51 | 68 | 33 | - | |||
| Short algorithm | QXP(YFWIL) X ≠ Pb | >500 | 276 | 105 | 7 | |||
| Predicted epitope | QQPFPQQPQQPFPQ | 6 | 12 | 2 | - | |||
. | . | Number of matchesin databases . | . | . | . | |||
|---|---|---|---|---|---|---|---|---|
| Search algorithm . | . | Gluten . | Hordein . | Secalin . | Avenin . | |||
| Algorithm 1 | Q4XPQ7X(YFWIL) | 52 | 48 | 8 | - | |||
| Algorithm 1 – Q4 | XXPQ7X(YFWIL) | 334 | 91 | 14 | 6 | |||
| Algorithm 1 – Q7 | Q4XPXX(YFWIL) | 286 | 142 | 60 | 11 | |||
| Algorithm 2 | Q4XPQ7XP(YFWIL) | 46 | 60 | 33 | - | |||
| Algorithm 2 – Q4a | XXPQ7XP(YFWIL) | 262 | 196 | 89 | - | |||
| Algorithm 2 – Q7 | Q4XPXXP(YFWIL) | 51 | 68 | 33 | - | |||
| Short algorithm | QXP(YFWIL) X ≠ Pb | >500 | 276 | 105 | 7 | |||
| Predicted epitope | QQPFPQQPQQPFPQ | 6 | 12 | 2 | - | |||
Algorithm 2 without the specification of a Q at position 4 predicts the known gliadin α9 epitope.
A proline at p2 in this algorithm inhibits deamidation of the glutamine.
The search algorithms reveal many matches in the gluten, hordeins, and secalin sequences but very few in the avenin sequences. The predictive algorithm 2 (QXPQXP[YFWIL]) and the less strict variants of that algorithm have no matches in the avenin database. The novel T cells stimulatory gluten peptide (QQPFPQQPQQPFPQ) is also found in the hordeins and secalin but not in the avenins. X stands for any amino acid.