Chemistry in a microenvironment of low pH, generated with the aid of an immobilized proteinase
| Autor: | John H. Haskell, Marc S. Silver |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Chemical Phenomena
Immobilized enzyme Phenylalanine Biophysics Buffers Hydrazide Biochemistry Diffusion chemistry.chemical_compound Hydrolysis Structural Biology Collodion Chymotrypsin Prodrugs Molecular Biology Alanine Acidic Region Chromatography Chemistry Buffer solution Hydrogen-Ion Concentration Enzymes Immobilized Solutions Kinetics Hydrazines Membrane Tyrosine Nuclear chemistry |
| Zdroj: | Biochimica et Biophysica Acta (BBA) - Protein Structure and Molecular Enzymology. 1039:25-32 |
| ISSN: | 0167-4838 |
| DOI: | 10.1016/0167-4838(90)90222-2 |
| Popis: | α-Chymotrypsin, when immobilized in a collodion membrane, exhibits high activity and remarkable stability. When the immobilized proteinase is exposed to 15 mM ethyl N- acetyl - l - tyrosinate in dilute pH 8.5 buffer it generates a microenvironment which, indicator studies suggest, has an effective pH of ≈4. The presence of this locally highly acidic region produces a marked increase in the rate of hydrolysis of BzPhealAla dissolved in the buffer solution (BzPhealAla is the acylhydrazide obtained from the reaction between N- benzoyl - l - phenylalaninal and N- acetyl - l - alanine hydrazide ). The observed rate is 10-times greater than in comparable control experiments incorporating a concentrated buffer solution, in which a pH-gradient does not form. The enhanced hydrolysis rate is quantitatively explained if it is attributed to the ≈ 20 μl of pH 4 solution within the membrane. Other experimental data are also consistent with this hypothesis. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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