Pathways of Adenosine Triphosphate Production by Calf Lens Homogenates

Abstract

IN previous work we investigated the phosphorylations occurring in homogenates of various zones of the crystalline lens of a calf incubated with glucose-6-phosphate¹. The transformation of adenosine diphosphate (ADP) into adenosine triphosphate (ATP) was measured by isolation of the nucleotides by column chromatography ‘Dowex 1 × 8’ 200–400 mesh (formate form). The application of such a method is rendered possible by the very feeble ATPase activity of the lens. We saw that the intensity of phosphorylation diminished on passing from the anterior zone, constituted by the epithelium and young fibres, towards the older fibres of the cortical and central zone. The aim of the present work was to determine the extent of phosphorylation due to anaerobic glycolysis, the Krebs cycle and possibly to the pentose cycle by a transdehydrogenation reaction: reduced coenzyme 2 + coenzyme 1 → reduced coenzyme 1 + coenzyme 2.