Phospholipase A2 inhibition by alkylbenzoylacrylic acids
| Autor: | G. Peinhardt, Thomas Kohler, Matthias Kirchner, M. Heinisch, R. Hirschelmann, P. Nuhn |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Blood Platelets
Neutrophils Swine Leukotriene B4 Biochemistry Phospholipases A Acylation Thromboxane A2 chemistry.chemical_compound Manoalide Phospholipase A2 Hydroxyeicosatetraenoic Acids Animals Humans Pancreas Pharmacology biology Dissociation constant Kinetics Phospholipases A2 Acrylates chemistry Snake venom Enzyme inhibitor biology.protein lipids (amino acids peptides and proteins) Arachidonic acid Snake Venoms |
| Zdroj: | Biochemical Pharmacology. 44:805-813 |
| ISSN: | 0006-2952 |
| DOI: | 10.1016/0006-2952(92)90419-j |
| Popis: | 3-(4-Alkylbenzoyl)acrylic acids (ABAAs) were synthesized by acylation of alkylbenzenes with maleic anhydride and then screened in vitro for inhibition of phospholipase A2 (PLA2) from snake venom and from porcine pancreas. The inhibitory potency of ABAAs increased with the length of the alkyl residues resulting in IC50 values of between 10(-7) and 10(-4) mol/L. The most potent inhibitors of the snake venom PLA2 were the 4-(n)-hexadecyl and octadecyl (OBAA) derivatives. Kinetic experiments referred to a time-dependent inhibitory reaction. Irreversibility was examined by dilution and dialysis. A molar ratio of inactivation of OBAA of nearly 20 was estimated. Double reciprocal replots of the apparent inactivation constants to the concentration of OBAA gave a (pseudo) first order rate constant of inactivation of 2.3 min-1. For the dissociation constant of the enzyme-inhibitor intermediate, a value of 6 x 10(-6) mol/L was obtained. On the other hand, the PLA2 from porcine pancreas seemed hardly to be inhibited by ABAAs. The present data are discussed in relation to the proposed model for PLA2 inactivation by manoalide. In human PMNs leukotriene B4 and 5-HETE production was essentially reduced. In human platelets the thrombin-induced TxA2 production was reduced. Since these effects disappeared after addition of arachidonic acid, these findings refer to a PLA2 inhibition. The immunologically induced bronchospasm in guinea pigs was significantly and dose-dependently inhibited by OBAA. This indicates that ABAAs might be useful in treating allergic diseases, such as asthma, eczema, allergic shock and others. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|