Gas Chromatography with Modified pH-Sensitive Pellets in Evaluating Esterase Activity of Carbonic Anhydrase III Enzyme: Drug Discovery Approach

Abstract

Antagonism of carbonic anhydrase, isozyme 3 (CAIII) has a strong potential in treating obesity, hyperlipidemia and cancer. The enzyme has a very low activity in hydrating carbon dioxide which makes it unresponsive to the majority of methods used against other CAs. In this study, a new evaluation method based on gas chromatography (GC) is considered for the screening of the inhibitory activity of various nicotinic acid derivatives against CAIII using immobilized pH-sensitive matrix pellets. The CA inhibitory activity of 14 nicotinic acid derivatives were studied using a GC method. The percentage of the inhibition of nicotinic acid derivatives against CA was calculated and found to be related to the molecular volume of the candidate inhibitor. This might be due to the limited size of CAIII’s active site. A lower molecular volume correlates with the inhibitory effect of each candidate. This approach of analysis might be utilized in developing sensitive GC methods for other enzymes attributed with pH change in their media. Particularly, for those which require accurate and sensitive assay methods.