Evidence for the glycoprotein nature of kidney renin.
The glycoprotein nature of renin isolated from either rabbit or human kidney has been demonstrated by affinity chromatography on concanavalin A-Sepharose. The bulk of rabbit renin activity bound to concanavalin A is released by 20 to 50 mM alpha-methyl-D-mannoside. Adsorption of renin is prevented by periodate oxidation prior to chromatography. Mild acid treatment (pH 2.5) prior to chromatography does not alter the concanavalin A binding profile although the pI values of native rabbit renin (5.1-5.6) are shifted into a broader distribution (4.7-6.4). The molecular weight values of rabbit renin obtained by gel filtration and those from zone centrifugation are identical (37000 +/- 1000), consistent with a low percent of carbohydrate in the glycoprotein. A hydrophobic contribution to the binding of renin by concanavalin A is evident since, in the presence of mM Ca2+ and Mn2+, higher concentrations of alpha-methyl-D-mannoside are required to affect the same release of renin at 23 degrees C compared to that at 4 degrees C. Furthermore, 25% ethylene glycol releases renin in the absence of alpha-methyl-D-mannoside. It is concluded that renin contains a small number of carbohydrate residues in relatively close proximity to a hydrophobic surface which enhances the interaction with concanavalin A.
D000818:Animals; D002021:Buffers; D002846:Chromatography, Affinity; D003208:Concanavalin A; D006023:Glycoproteins / Q000302:isolation & purification / Q000378:metabolism; D006801:Humans; D007668:Kidney / Q000201:enzymology; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010504:Periodic Acid; D011817:Rabbits; D012083:Renin / Q000302:isolation & purification / Q000378:metabolism; D013329:Structure-Activity Relationship; D013696:Temperature; D014461:Ultracentrifugation
D002021:Buffers; D006023:Glycoproteins; D010504:Periodic Acid; D003208:Concanavalin A; D012083:Renin