Calcium-stimulated adenosine triphosphatase in the microsomal fraction of tooth germ from porcine fetus

Area of Science:

• Biochemistry
• Cell Biology
• Developmental Biology

Background:

• Calcium ions (Ca2+) play critical roles in cellular processes, including tooth development.
• Understanding the enzymes involved in calcium transport is essential for comprehending tooth germ formation.

Purpose of the Study:

• To characterize and localize a Ca2+-activated ATPase in the porcine fetal tooth germ.
• To investigate the enzyme's kinetic properties and cofactor requirements.

Main Methods:

• Enzyme assays using microsome fractions from porcine fetal tooth germ.
• Determination of kinetic parameters (Km, Vmax) and optimal conditions (pH, ion concentrations).
• Subcellular and tissue localization studies.

Main Results:

• A Ca2+-activated ATPase (ATP phosphohydrolase) was identified and characterized.
• Optimal activity observed at 0.5–1.0 mM CaCl2 and pH 9.2, with ATP as the preferred substrate.
• The enzyme is localized in the smooth endoplasmic reticulum and enamel organ, specifically ameloblasts, stratum intermedium, and stellate reticulum.

Conclusions:

• The identified Ca2+-ATPase is likely involved in regulating intracellular calcium levels during tooth germ development.
• Its localization suggests a role in processes such as enamel formation and mineralization.