| Autor: |
Menegatti, Enea, Boggian, Marisa, Ascenzi, Paolo, Luisi, Pier Luigi |
| Zdroj: |
Journal of Enzyme Inhibition; 1987, Vol. 2 Issue: 1 p67-71, 5p |
| Abstrakt: |
The effect of pH and temperature on the association equilibrium constant (Ka) for the binding of the trypsin inhibitor from white mustard (Sinapis alba L.) seeds (MTI) to bovine β-trypsin (EC 3.4.21.4) has been investigated. On lowering the pH from 9 to 3, values of Ka for MTI binding to bovine β-trypsin decrease thus reflecting the acid-pK and-midpoint shifts, upon inhibitor association, of two independent ionizable groups, and of a three-proton transition, respectively. At pH 8.0, values of thermodynamic parameters for MTI binding to bovine β-trypsin are: Ka = 4.5 × 108M-1, ΔG° = - 11.6kcal/mol, and ΔS° = +53 entropy units (all at 21°C); and ΔH° = + 4.1 kcal/mol (temperature independent between 5°C and 45°C). Binding properties of MTI to bovine β-trypsin have been analyzed in parallel with those concerning macromolecular inhibitor association to serine (pro)enzymes. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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