Simultaneous purification and properties of dehydropeptidase-I and aminopeptidase-M from rat kidney.
Two peptidases, dehydropeptidase-I and aminopeptidase-M were solubilized from rat kidney microsomes by treatment with papain and separated by DE-52 ion exchange chromatography. Each enzyme was further purified by Sephacryl S-300 gel filtration and affinity chromatography on Con-A Sepharose. Purified dehydropeptidase-I and aminopeptidase-M were homogeneous by SDS-polyacrylamide gel electrophoresis, and their molecular weights were estimated by gel filtration to be 148,000 and 240,000, respectively; both being homodimer, with a 78,000 subunit for the former and a 120,000 subunit for the latter. Both dehydropeptidase-I and aminopeptidase-M were capable of hydrolyzing L-leucyl-L-leucine with a Km valve of 1.1 mM and 1.7 mM, respectively, although the hydrolyzing activity of aminopeptidase-M was much higher than that of dehydropeptidase-I. Aminopeptidase-M was inhibited by bestatin, and dehydropeptidase-I was significantly inhibited by cilastatin. Dehydropeptidase-I catalyzed the conversion of leukotriene D4 to E4 and the hydrolysis of L-cystinyl-bis-glycine, but aminopeptidase-M did not to any appreciable extent. The physiological significance of dehydropeptidase-I was pointed out and discussed.
Hirota
T
T
Nishikawa
Y
Y
Takahagi
H
H
Igarashi
T
T
Kitagawa
H
H
D000626:Aminopeptidases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D000818:Animals; D018826:CD13 Antigens; D004150:Dipeptidases / Q000037:antagonists & inhibitors / Q000302:isolation & purification*; D005978:Glutathione / Q000378:metabolism; D007668:Kidney / Q000201:enzymology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013189:SRS-A / Q000378:metabolism
D013189:SRS-A; D000626:Aminopeptidases; D018826:CD13 Antigens; D004150:Dipeptidases; C038937:dipeptidase; D005978:Glutathione