1H‐indazole molecules reduced the activity of human erythrocytes carbonic anhydrase I and II isoenzymes

Abstract

Carbonic anhydrase (CA) is an important metabolic enzyme family closely related to many physiological and pathological processes. Currently, carbonic anhydrase inhibitors are the target molecules in the treatment and diagnosis of many diseases. In present study, we investigated the inhibitory effects of some indazole molecules on the CA-I and CA-II isoenzymes isolated from human erythrocytes. We showed that human CA-I and CA-II activities were reduced by of some indazoles at low concentrations. IC values, K constants, and inhibition types for each indazole molecule were determined. The indazoles showed K constants in a range of 0.383 ± 0.021 to 2.317 ± 0.644 mM, 0.409 ± 0.083 to 3.030 ± 0.711 mM against CA-I and CA-II, respectively. Each indazole molecule exhibited a noncompetitive inhibition effect. Bromine- and chlorine-bonded indazoles were found to be more potent inhibitory effects on carbonic anhydrase isoenzymes. In conclusion, we conclude that these results may be useful in the synthesis of carbonic anhydrase inhibitors.

Possibility of Venous Serum Cl− Concentration ([Cl−]s) as a Marker for Human Metabolic Status: Correlation of [Cl−]s to Age, Fasting Blood Sugar (FBS), and Glycated Hemoglobin (HbA1c)

“…H + produced from CO 2 in erythrocytes bounds to Hb, while HCO 3 − produced from CO 2 in erythrocytes is excreted to the serum in blood (the extracellular space of erythrocytes) via the AE-mediated process, participating in uptake of Cl − into erythrocytes from the serum in blood [6,10]. CAs expressed in erythrocytes are I and II isozymes of CAs: CAI and CAII [35]. This Cl − movement into erythrocytes across the plasma membrane is well-known as "Cl − shift": (1) in erythrocytes, the Cl − concentration increases associated with a decrease of HCO 3 − concentration; (2) in the serum, [Cl − ] s concentration decreases associated with an increase of [HCO 3 − ] s .…”

“…The CO 2 produced in metabolic cells moves into erythrocytes [6,10,19,30,31]. Then, CAs facilitate the converting process of CO 2 to H + and HCO 3 − (CO 2 + H 2 O → H + HCO 3 − ) in erythrocytes: I and II isozymes of CA (CAI and CAII) are expressed in erythrocytes [35]. The HCO 3 − is excreted from erythrocytes to the serum in blood (the extracellular space of erythrocytes) via the AE-mediated pathway, while the produced H + bounds to Hb (c.f., Figure 4) [6,10,19,30,31].…”

Some characteristics of new and innovative COX inhibitor derivatives: Potent hCA‐I and hCA‐II inhibitors supported by molecular docking studies

“…Isoenzymes I and II were purified from human erythrocytes using the sepharose‐4B‐L‐tyrosine sulfanilamide affinity column at 280 nm as in our previous studies. [ 54–56 ] The activities of isoenzymes were measured as in Wilbur–Anderson, [ 57 ] purification and quantitative protein determination was done as in Bradford method. [ 58 ] The purity of The hCA‐I and hCA‐II isoenzymes was checked by Laemmli's SDS‐PAGE method (3%–8%), [ 59 ] imaged as a single protein band at approximately 29 kDa.…”

Inhibition Effect of Eosin Y on Carbonic Anhydrase (CA) I and II Isoenzymes Purified from Human Erythrocytes

“…The affinity column was equilibrated using 25 mM Tris-HCl / 0.1 M Na2SO4 (pH 8.7) buffer solution. Preparation of human erythrocyte hemolysate (40 mL) and purification of CAI and CAII were done as in previous study (Alım, 2018). During the purification, the elution of CA I and CA II was monitored by measuring the absorbance at 280 nm.…”

“…Since there are 16 isoenzymes of the carbonic anhydrase enzyme, most CA inhibitors are non-specific and have numerous side effects. (Alım, 2018). In order to prevent this, inhibitors specific to isoenzymes need to be designed.…”