Brush Border Particulates of Renal Tissue
Francis Binkley 1,
Neva King 1,
Elizabeth Milikin 1,
Reba K. Wright 1,
C. H. O'Neal 1, and
Ina Jane Wundram 1
1 Departments of Biochemistry and Anatomy, Emory University, Atlanta, Georgia 30322
Particulates containing a large part of the alkaline phosphatase activity of renal tissue were separated from homogenates and from ribosomal preparations by zonal centrifugation. The particles had a high content of phospholipid and cholesterol that was not removed by treatment with I percent deoxycholate. Enzymatic activities concentrated with the particles were the alkaline phosphatase, a peptidase resistant to proteolysis, glucose-6-phosphatase, inorganic pyrophos-phatase, and adenosine triphosphatase. The particles accumulated leucine with no stimulation from soluble factors and with inhibition by other amino acids; the accumulation was stimulated by adenosine triphosphate and was not inhibited by puromycin. The particles appear to be derived from the membranes of the brush borders of tubular cells.
