Biochemical properties of the house dust mite (HDM) extracts in the concentration applied in vitro
| Citeq | ALK | Greer | |
| Der p1 content (ng) | 6.25 | 50 | 81 |
| Der p2 content (ng) | 1 | 22.2 | 428.9 |
| Protein content (μg/ml) | 2.64 | 12 | 50 |
| Total protease activity (U/ml) | 5±0.5 | 5±1.5 | 5±0.7 |
| Protease activity after HI (U/ml) (% of total) | 0.9±0.2 (18%) | 1.6±0.2 (32%) | 1.4±0.3 (28%) |
| Protease activity remaining after AEBSF treatment (U/ml) (% of total) | 2±0.3 (40%) | 4.2±1.4 (84%) | 5±0.6 (99.9%) |
| Protease activity remaining after E64 treatment (U/ml) (% of total) | 4±0.9 (80%) | 5±1.9 (99.9%) | 4.8±0.8 (96%) |
| Serine protease activity (103 mean V/ml*) | 2222±45 | 2087±5 | 162.7±58 |
| Serine protease activity remaining after AEBSF treatment (103 mean V/ml*) | 0 | 0 | 0 |
| Cysteine protease activity (103 mean V/ml*) | 892±1 | 1191±14 | 95±2 |
| Cysteine protease activity remaining after E64 treatment (103 mean V/ml*) (% of total) | 468±6 (52.4%) | 747±3 (62.7%) | 80±2 (84%) |
| Exochitinase (ß-N-acetylglucosaminidase) levels (10−6 U/ml) | 2±0.5 | 2400±4 | 1800±120 |
| Exochitinase (ß-N-acetylglucosaminidase) levels after HI (10−6 U/ml) | 0.4±0.4 | 18±0.6 | 60±0.6 |
| Exochitinase (chitobiosidase) levels (10−6 U/ml) | 1±0.03 | 800±6 | 300±18 |
| Exochitinase (chitobiosidase) levels after HI (10−6 U/ml) | 1±0.1 | 18±0.6 | 120±4.8 |
| Endochitinase levels (10−6 U/ml) | 1±0.03 | 400±4 | 300±18 |
| Endochitinase levels after HI (10−6 U/ml) | 1±0.01 | 20±2 | 60±3 |
| Endotoxin (LPS) level (EU/ml) | 7.1 | 0.28 | 31.65 |
The table shows several aspects of the biochemical properties found in the HDM extracts when tested on human bronchial epithelial cells (16HBE). All data were obtained from three independent experiments and calculated after exposure concentrations of the HDM extracts in the cell culture.
↵* Arbitrary unit.
AEBSF, 4-(2-aminoethyl) benzenesulfonyl fluoride hydrochloride; Der p, Dermatophagoides pteronyssinus; EU, endotoxin unit; HI, heat inactivation; LPS, lipopolysaccharide; U, unit.