Pyruvate kinase allostery resist hyperglycemia, obesity and inflammation by inducing TCA vortex and glucose U turn

Abstract

ATP is the final product of glycolysis and the TCA cycle. However, the counter-regulation of glycosis and TCA by ATP is poorly understood. Here we show that ATP analog celastrol (CLT) binds to the ATP binding pocket on pyruvate kinase PKM (PKM) while inducing allosteric regulation of PKM. Quantum calculation predicts hydrogen bond formation between CLT and asparagine. Liquid chromatography-mass spectrometry further identifies PKM as CLTs target. The inhibition of PKM is stronger and longer for CLT while weak and short for ATP. Notably, CLT-PKM interaction perfectly underlies the hypoglycemic effects by forming glucose carbon flux U turn before PKM. Besides, the PKM allostery induces a tricarboxylic acid (TCA) vortex which could promote amino acid and lipid degradation as the energy compensation, leading to a significant weight loss. Additionally, CLT exerts efficient antioxidant effects by altering the glucose flux to strengthen the pentose phosphate pathway. Consequently, the CLT-PKM interaction vividly reproduces the ATP-PKM interaction named "ATP resistance" in the diabetes pathogenesis.