Abstract
Distribution of the Mg2+ -dependent, HCO3− -stimulated ATPase (HCO3− -ATPase) was investigated in sub-cellular fractions of the tissue of the human thyroid gland. It was found that especially high enzymatic activity is characteristic of mitochondria and the endoplasmic reticulum. Correlation between various pathologies of the thyroid and HCO3− -ATPase activity was demonstrated. The activity was evaluated using the difference between active and passive ATPase. During development of the various pathologies, the sub-cellular fractions of the gland showed uneven alterations of HCO3−-ATPase activity. Intriguingly, the enzyme kinetic parameters are also changed, i.e. in the different pathologies both enzyme activity and its affinity towards bicarbonate ions are altered. This raises the question whether pathology is caused by, or results in, changes in the enzyme at the molecular level.
Declaration of interest: The authors report no conflict of interest. The authors alone are responsible for the content and writing of the paper.