Table 1.
Binding of N1-, N3-, Iso1-, and Iso3-HSA to different integrins as measured by a competitive binding assay using a CisoDGRC-HRP conjugate
| Competitor | Competitive binding (Ki a values in nM) to | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| αvβ3 |
αvβ5 |
αvβ6 |
αvβ8 |
α5β1 |
||||||
| n b | Ki | n | Ki | n | Ki | n | Ki | n | Ki | |
| N1-HSA | 1 | >3,000 c | nd d | nd | nd | nd | ||||
| N1-HSA (37 °C) e | 2 | 3.9 ± 0.9 | nd | nd | nd | nd | ||||
| N3-HSA | 1 | >3,000 | nd | nd | nd | nd | ||||
| N3-HSA (37 °C) | 2 | 6.1 ± 1.9 | nd | nd | nd | nd | ||||
| Iso1-HSA | 6 | 4.8 ± 0.9 (1) f |
3 | 25.5 ± 5.6 (5.3) |
4 | 1,445 ± 666 (301) |
2 | 29,086 ± 1875 (6059) |
3 | 172 ± 29 (36) |
| Iso3-HSA | 3 | 4.7 ± 1.8 (1) |
2 | 7.1 ± 1.6 (1.5) |
3 | 127 ± 43 (27) |
4 | 116 ± 4 (25) |
3 | 39 ± 5.1 (8.3) |
| *HSA | 1 | >10,000 | 1 | >10,000 | 1 | >10,000 | 1 | >10,000 | 1 | >10,000 |
a
Ki, equilibrium dissociation constant of the competitor (mean ± SE). Ki was determined using a competitive binding assay as described previously [24].
b
n, number of independent experiments (each in duplicate).
c
>, maximum concentration tested that had no inhibitory effect.
d
nd, not determined.
e
37 °C, the conjugate was incubated overnight at 37 °C in 0.1 M ammonium bicarbonate buffer, pH 8.5, to favor NGR-to-isoDGR conversion.
f
Relative values to αvβ3 Ki.