title: Adenosine deaminase-complexing protein from bovine kidney. Isolation of two distinct subunits.
abstract: We have isolated a complex of two proteins from bovine kidney that bind to adenosine deaminase immobilized on Sepharose 4B. One protein, with Mr = 110,000, comigrates on both PAGE and SDS-PAGE gels with complexing protein isolated from rabbit kidney by the method of Schrader et al. (Schrader, W.P., Harder, C. M., and Schrader, D. K. (1983) Comp. Biochem. Physiol. B Comp. Biochem. 75, 119-126). The second protein has a Mr = 70,000. Both proteins bind to the adenosine deaminase-Sepharose but not to a control resin of bovine serum albumin bound to Sepharose. Based on a comparison of partial and complete denaturation on SDS-PAGE the two proteins appear to be bound to each other. At adenosine concentrations of 0.5-1 mM the isolated complexing protein increases small subunit adenosine deaminase catalytic activity by 20-30%. There may be some inhibition of catalytic activity at low adenosine concentrations. We have designated the 110,000 Mr protein CP-I, the 70,000 Mr protein CP-II and the complex of these two CP.
mesh_terms: D000243:Adenosine Deaminase / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification*; D002417:Cattle; D018819:Dipeptidyl Peptidase 4; D004591:Electrophoresis, Polyacrylamide Gel; D007668:Kidney / Q000032:analysis*; D046911:Macromolecular Substances; D008970:Molecular Weight; D009700:Nucleoside Deaminases / Q000378:metabolism*
chemical_list: D002352:Carrier Proteins; D046911:Macromolecular Substances; D018819:Dipeptidyl Peptidase 4; D009700:Nucleoside Deaminases; D000243:Adenosine Deaminase