Atypical cytoplasmic distribution of FXIII-A in THP-1 cells
| . | Experiment 1 . | Experiment 2 . | ||||
|---|---|---|---|---|---|---|
| LDH, % . | NAG, % . | FXIII-A, % . | LDH, % . | NAG, % . | FXIII-A, % . | |
| C | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| PA | 1.4 | 39.9 | 0.0 | 10.3 | 44.2 | 4.5 |
| PB | 2.8 | 41.0 | 35.3 | 24.2 | 67.4 | 68.8 |
| . | Experiment 1 . | Experiment 2 . | ||||
|---|---|---|---|---|---|---|
| LDH, % . | NAG, % . | FXIII-A, % . | LDH, % . | NAG, % . | FXIII-A, % . | |
| C | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 | 100.0 |
| PA | 1.4 | 39.9 | 0.0 | 10.3 | 44.2 | 4.5 |
| PB | 2.8 | 41.0 | 35.3 | 24.2 | 67.4 | 68.8 |
Nonadherent THP-1 cells were metabolically labeled and then permeabilized with streptolysin O (SLO) by the preactivation protocol (PA) or by the prebinding and washing protocol (PB). The enzyme activities of LDH and β-N-acetylglucosaminidase (NAG) and the radioactivity in (immunoprecipitated) FXIII-A recoverable in the cell ghosts are expressed as the percentage of the total activities in the cell before permeabilization. In experiment 1, there was extensive permeabilization by either protocol (judged by LDH recovery) with substantial preservation of endomembranes (NAG). However, a substantial proportion of FXIII-A remained cell associated in the prebinding and washing protocol. In a second experiment, the extent of SLO permeabilization was lower, probably because the activity of SLO can be difficult to standardize. However, it was again apparent that the prebinding and washing protocol resulted in a similar retention of FXIII-A to that of NAG.