No abstract

No abstract

No abstract

By means of gel filtration and ion exchange chromatography on calcium-saturated Chelex-100, a calcium-binding fraction was isolated from the mantle edge of the freshwater snail lymnaea stagnalis. This fraction was not present in other tissues. Treatment with trypsin caused a disappearance of the calcium-binding capacity, proving that the active substance in this fraction is a protein (calcium-binding protein; CaBP). Removal of the growth hormone-producing neuroendocrine light green cells resulted in a strong decrease of the amount of CaBP. It is concluded that L. stagnalis possesses a hormone-dependent CaBP, probably responsible for the maintenance of a high calcium concentration in that part of the mantle that produces the outer crystalline layer of the shell.

A rapid 3-step method is given to purify partially hamster molar alkaline phosphatase. Molecular weight was 50,200 and isoelectric point 3.7. The alkaline phosphatases in the mesenchymal and ectodermal parts of the tooth are probably identical.