Penicillin acylase-catalyzed ampicillin synthesis using a pH gradient: A new approach to optimization
| Autor: | Erik de Vroom, Fred van Rantwijk, Roger A. Sheldon, Luuk M. van Langen, M. I. Youshko, Vytas K. Švedas |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Quality Control
Stereochemistry education Glycine Penicillanic Acid Bioengineering Penicillin amidase Sensitivity and Specificity Applied Microbiology and Biotechnology Catalysis Cell Line chemistry.chemical_compound Hydrolysis Amide Ampicillin mental disorders Escherichia coli medicine Antibacterial agent Chemistry Hydrogen-Ion Concentration Penicillin Models Chemical Penicillin Amidase Protons Saturation (chemistry) psychological phenomena and processes Biotechnology medicine.drug Nuclear chemistry |
| Zdroj: | Biotechnology and Bioengineering. 78:589-593 |
| ISSN: | 1097-0290 0006-3592 |
| DOI: | 10.1002/bit.10234 |
| Popis: | The penicillin acylase-catalyzed synthesis of ampicillin by acyl transfer from D-(-)-phenylglycine amide (D-PGA) to 6-aminopenicillanic acid (6-APA) becomes more effective when a judiciously chosen pH gradient is applied in the course of the process. This reaction concept is based on two experimental observations: 1) The ratio of the initial synthesis and hydrolysis rates (V(S)/V(H)) is pH-dependent and exhibits a maximum at pH 6.5-7.0 for a saturated solution of 6-APA; 2) at a fixed 6-APA concentration below saturation, V(S)/V(H) increases with decreasing pH. Optimum synthetic efficiency could, therefore, be achieved by starting with a concentrated 6-APA solution at pH 7 and gradually decreasing the pH to 6.3 in the course of 6-APA consumption. A conversion of 96% of 6-APA and 71% of D-PGA into ampicillin was accomplished in an optimized procedure, which significantly exceeds the efficiency of enzymatic synthesis performed at a constant pH of either 7.0 or 6.3. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text