Purification and properties of the sodium–potassium transport adenosinetriphosphatase from the rectal gland of the spiny dogfish squalus acanthias

• Published in: Journal of Supramolecular Structure
• Main Author: Hokin, Lowell E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1973
• Subjects: spiny dogfish; Squalus acanthias
• Online Access: http://dx.doi.org/10.1002/jss.400010409; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjss.400010409; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jss.400010409

Abstract The (Na + K)–activated adenosinetriphosphatase (NaK ATPase) has been purified from Lubrol extracts of membranes from the rectal glands of Squalus acanthias. The specific activity of the purified enzyme is 2 to 3 times that previously reported by others after correction of their specific activities for detergent activation. The yield of the enzyme from the membranes is 70%. The enzyme is highly stable both at 0° and in the frozen state. Ninety‐five percent of the enzyme consists of two subunits–the catalytic subunit with a MW of 97,000 and a glycoprotein with a MW of 55,000. At the last stage of purification the enzyme reverts to various membranous forms: the thickness of the membrane is about 80 Å; projections (probably the glycoprotein) of about 40 Å in diameter are seen at regular intervals.