Healthy and Gestational Diabetic Human Placental Fructose 1,6 Bisphosphate Aldolase; Comparative Investigation of Kinetic Properties and Inhibition Effects of DHAP, ATP, and Mg<sup>+2</sup> ion

Abstract

Fructose-1,6-bisphosphate aldolase plays an effective role in glucose metabolism and gluconeogenic pathway, and reversibly catalyzes the split of fructose 1,6-bisphosphate into the triose phosphates D-glyceraldehyde phosphate and dihydroxyacetone phosphate. Aldolase has 160 kDa molecular weight and three tissue specific isozymes. Gestational diabetes mellitus is defined as glucose intolerance that begins or is first detected during pregnancy. The placenta is a temporary established organ that operates exclusively for the time of pregnancy. It acts as a natural barrier between the maternal and fetal blood circulations and performs a wide range of endocrine and transport functions. In diabetes, the placenta undergoes a variety of structural and functional changes. Healthy and gestational diabetic human placental fructose-1, 6-bisphosphate aldolases were purified and investigated the substrate kinetic properties, in the previous studies. In this comparative study, we wanted to carry out characteristics of inhibition kinetics of aldolase in healthy and diabetic human placenta. The specific activity was defined as the number of activity units per mg of protein. Inhibition kinetics of fructose-bisphosphate aldolase was studied using dihydroxyacetone-phosphate, adenosine triphosphate, and magnesium ion as inhibitors. For healthy placental Aldolase it was detected that, adenosine triphosphate is partial competitive; dihydroxyacetone-phosphate is noncompetitive and magnesium metal is pure-competitive inhibitor. It was found that, dihydroxyacetone-phosphate is competitive; adenosine triphosphate is partial competitive and magnesium is partial competitive inhibitor of gestational diabetic human placental Aldolase.