Characterization of prolidase I and II purified from normal human erythrocytes: comparison with prolidase in erythrocytes from a patient with prolidase deficiency.
The effect of various sulfur-containing amino acids on the activities of prolidase isoenzymes I and II isolated from erythrocytes of healthy individuals, and erythrocyte lysates from a patient with prolidase deficiency was investigated. The activity of prolidase I against glycylproline was strongly enhanced by D: -methionine. L: -Methionine and D: ,L: -methionine slightly enhanced the activity at low concentration, but N-acetyl-L: -methionine had no effect. D: -Ethionine, L: -ethionine, and D: ,L: -ethionine also enhanced the activity of prolidase I. D: ,L: -Homocysteine enhanced the activity at low concentration, but inhibited the activity at 50 mM: . The activity of prolidase II against methionylproline was enhanced by D: -methionine, D: ,L: -methionine, and L: -methionine, but N-acetyl-L: -methionine had no effect. D: -Ethionine and D: ,L: -ethionine strongly enhanced the activity of prolidase II compared with L: -ethionine; D: ,L: -homocysteine weakly enhanced the activity. D: ,L: -Homocysteine-thiolactone inhibited the activities of prolidase I and II in a concentration-dependent manner. The effect of various sulfur-containing amino acids on prolidase activity against methionylproline in erythrocyte lysates from a patient with prolidase deficiency was almost the same as that on prolidase II. The kinetics of the activities of prolidase I, II, and patient prolidase were also studied. Their K (m) values were changed by adding sulfur-containing amino acids, but V (max) values were unchanged.
Uramatsu
Soichiro
S
Department of Anesthesiology and Critical Care Medicine, Kochi Medical School, Nankoku-shi, Japan.
Liu
Gang
G
Yang
Qing
Q
Uramatsu
Mutsumi
M
Chi
Haidong
H
Lu
Jincai
J
Yamashita
Koichi
K
Kodama
Hiroyuki
H
D000603:Amino Acids, Sulfur / Q000378:metabolism*; D004150:Dipeptidases / Q000097:blood / Q000172:deficiency* / Q000302:isolation & purification / Q000378:metabolism*; D004151:Dipeptides / Q000378:metabolism; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D007527:Isoenzymes; D007700:Kinetics; D013237:Stereoisomerism; D013379:Substrate Specificity
D000603:Amino Acids, Sulfur; D004151:Dipeptides; D007527:Isoenzymes; D004150:Dipeptidases; C022449:proline dipeptidase