title: Isoelectric focusing patterns of urinary kallikrein in Dahl salt-hypertension susceptible and resistant rats.
abstract: Dahl salt-sensitive (S) rats which are susceptible to hypertension have lower urinary kallikrein excretion than salt-resistant (R) rats which are not susceptible. Some physicochemical characteristics of partially purified urinary kallikrein were compared between the S and R strains. The isoelectric focusing pattern of S kallikrein was shifted so that a higher proportion of enzyme was present in isoelectric forms that had higher pI values compared to the pattern for R kallikrein. This strain difference was unique to urinary kallikrein; it was not seen in kallikrein extracted from salivary glands. The isoelectric focusing pattern for R urinary kallikrein could be converted to an S-type pattern by treatment with neuraminidase, which suggests that the differing isoelectric focusing patterns arose from differences in the sialic acid content of the kallikrein. The S kallikrein was slightly more heat-labile than R kallikrein, which was also compatible with the lower sialic acid content of the S enzyme. Tests involving the active site of the enzyme (Km values, pH curves, and heat of activation) were identical for the S and R strains. It was concluded that the structural differences observed in urinary kallikrein between S and R strains were compatible with strain-specific posttranslational processing of the enzyme.
mesh_terms: D000818:Animals; D004198:Disease Susceptibility; D006973:Hypertension / Q000139:chemically induced / Q000235:genetics* / Q000652:urine; D007525:Isoelectric Focusing; D007610:Kallikreins / Q000378:metabolism / Q000652:urine*; D007700:Kinetics; D009439:Neuraminidase / Q000652:urine; D010447:Peptide Hydrolases / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains / Q000235:genetics* / Q000378:metabolism; D012469:Salivary Glands / Q000378:metabolism; D012965:Sodium Chloride / Q000502:physiology*
chemical_list: D012965:Sodium Chloride; D009439:Neuraminidase; D010447:Peptide Hydrolases; C023073:tosylarginine methyl ester hydrolase; D007610:Kallikreins