TABLE 4.
Initial rate of peptide transport by L. lactis IL-1403 and its Opt mutants MLA and MLSa
| Strain or mutant | Rate of transport (nmol/min/mg of protein) with peptide
|
|||
|---|---|---|---|---|
| LPQY | RMPIQA | DGGFM | DRVYIHPFHL | |
| IL-1403 | 40 | 17 | 34 | 0 |
| MLA (OptA−) | 0 | 0 | 0 | 0 |
| MLS (OptS−) | ND | 18 | 39 | 0 |
a
Peptide concentration used for transport assays was 50 μM. The amino acids used to estimate the rate of uptake of LPQY, RMPIQA, DGGFM, and DRVYIHPFHL were Leu, Met, Met, and His, respectively. Each value represents the mean of two repetitions. ND, not determined.