TABLE 1.
Distributions of enzyme activities and protein in cytoplasm and periplasma
| Strain | Cell fraction measured | U enzymatic activity·g fresh yeast−1 ± SD (% of total)
|
mg protein·g fresh yeast−1 ± SD (% of total) | ||
|---|---|---|---|---|---|
| β-Galactosidase | PGI | Invertase | |||
| T1 | Cytoplasm | 13.3 ± 0.7 | 261 ± 15 | 3.7 | 65.4 ± 2.0 |
| Periplasm | 0.2 ± 0.1 (1.5) | 28.1 ± 2.5 (9.7) | 7.2 (66) | 63.8 ± 3.0 (49) | |
| T1-E | Cytoplasm | 272 ± 19 | 155 ± 7 | 2.5 | 61.6 ± 6.9 |
| Periplasm | 5.5 ± 1.3 (2.0) | 11.7 ± 1.1 (7.0) | 11.5 (82) | 61.6 ± 5.4 (50) | |
| K. lactis CBS2359 | Cytoplasm | 179 ± 29 | 128 ± 3 | 0.5 | 52.3 ± 3.2 |
| Periplasm | 32.6 ± 6.0 (15) | 17.8 ± 0.4 (12) | 1.9 (79) | 70.4 ± 4.6 (57) | |
a
Spheroplasts were prepared from the recombinant S. cerevisiae strains T1 and T1-E and K. lactis strain CBS2359. Enzyme activities and protein amounts in the cytoplasmic and cell wall/periplasmic fractions were assayed. Except for invertase data, results are averages ± standard deviations (SDs) of two to four assays. Values in parentheses are the enzyme activities or protein amounts found in the periplasm as percentages of the total enzyme activity or protein amount.