Abstract
An antibody preparation elicited against purified, lysosomal-solubilized NADH-cytochrome b5 reductase from rat liver microsomes was shown to interact with methemoglobin reductase of human erythrocytes by inhibiting the rate of erythrocyte cytochrome b5 reduction by NADH. The ferricyanide reductase activity of the enzyme was not inhibited by the antibody, suggesting that the inhibition of methemoglobin reductase activity may be due to interference with the binding of cytochrorme b5 to the flavoprotein. Under conditions of limiting concentrations of flavoprotein, the antibody inhibited the rate of methemoglobin reduction in a reconstituted system consisting of homogeneous methemoglobin reductase and cytochrome b5 from human erythrocytes. This inhibition was due to the decreased level of reduced cytochrome b5 during the steady state of methemoglobin reduction while the rate of methemoglobin reduction per reduced cytochrome b5 stayed constant, suggesting that the enzyme was not concerned with an electron transport between the reduced cytochrome b5 and methemoglobin. An antibody to purified, trypsin-solubilized cytochrome b5 from rat liver microsomes was shown to inhibit erythrocyte cytochrome b5 reduction by methemoglobin reductase and NADH to a lesser extent than microsomal cytochrome b5 preparations from rat liver (trypsin solubilized or detergent solubilized) and pig liver (trypsin solubilized). The results presented establish that soluble methemoglobin reductase and cytochrome b5 of human erythrocytes are immunochemically similar to NADH-cytochrome b5 reductase and cytochrome b5 of liver microsomes, respectively.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 600-607 |
| Number of pages | 8 |
| Journal | Archives of Biochemistry and Biophysics |
| Volume | 172 |
| Issue number | 2 |
| DOIs | |
| State | Published - 1976 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Molecular Biology
Cite this
Studies on methemoglobin reductase. Immunochemical similarity of soluble methemoglobin reductase and cytochrome b5 of human erythrocytes with NADH-cytochrome b5 reductase and cytochrome b5 of rat liver microsomes. / Kuma, Fumio; Prough, Russell A.; Masters, Bettie Sue Siler.
In: Archives of Biochemistry and Biophysics, Vol. 172, No. 2, 1976, p. 600-607.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Studies on methemoglobin reductase. Immunochemical similarity of soluble methemoglobin reductase and cytochrome b5 of human erythrocytes with NADH-cytochrome b5 reductase and cytochrome b5 of rat liver microsomes
AU - Kuma, Fumio
AU - Prough, Russell A.
AU - Masters, Bettie Sue Siler
PY - 1976
Y1 - 1976
N2 - An antibody preparation elicited against purified, lysosomal-solubilized NADH-cytochrome b5 reductase from rat liver microsomes was shown to interact with methemoglobin reductase of human erythrocytes by inhibiting the rate of erythrocyte cytochrome b5 reduction by NADH. The ferricyanide reductase activity of the enzyme was not inhibited by the antibody, suggesting that the inhibition of methemoglobin reductase activity may be due to interference with the binding of cytochrorme b5 to the flavoprotein. Under conditions of limiting concentrations of flavoprotein, the antibody inhibited the rate of methemoglobin reduction in a reconstituted system consisting of homogeneous methemoglobin reductase and cytochrome b5 from human erythrocytes. This inhibition was due to the decreased level of reduced cytochrome b5 during the steady state of methemoglobin reduction while the rate of methemoglobin reduction per reduced cytochrome b5 stayed constant, suggesting that the enzyme was not concerned with an electron transport between the reduced cytochrome b5 and methemoglobin. An antibody to purified, trypsin-solubilized cytochrome b5 from rat liver microsomes was shown to inhibit erythrocyte cytochrome b5 reduction by methemoglobin reductase and NADH to a lesser extent than microsomal cytochrome b5 preparations from rat liver (trypsin solubilized or detergent solubilized) and pig liver (trypsin solubilized). The results presented establish that soluble methemoglobin reductase and cytochrome b5 of human erythrocytes are immunochemically similar to NADH-cytochrome b5 reductase and cytochrome b5 of liver microsomes, respectively.
AB - An antibody preparation elicited against purified, lysosomal-solubilized NADH-cytochrome b5 reductase from rat liver microsomes was shown to interact with methemoglobin reductase of human erythrocytes by inhibiting the rate of erythrocyte cytochrome b5 reduction by NADH. The ferricyanide reductase activity of the enzyme was not inhibited by the antibody, suggesting that the inhibition of methemoglobin reductase activity may be due to interference with the binding of cytochrorme b5 to the flavoprotein. Under conditions of limiting concentrations of flavoprotein, the antibody inhibited the rate of methemoglobin reduction in a reconstituted system consisting of homogeneous methemoglobin reductase and cytochrome b5 from human erythrocytes. This inhibition was due to the decreased level of reduced cytochrome b5 during the steady state of methemoglobin reduction while the rate of methemoglobin reduction per reduced cytochrome b5 stayed constant, suggesting that the enzyme was not concerned with an electron transport between the reduced cytochrome b5 and methemoglobin. An antibody to purified, trypsin-solubilized cytochrome b5 from rat liver microsomes was shown to inhibit erythrocyte cytochrome b5 reduction by methemoglobin reductase and NADH to a lesser extent than microsomal cytochrome b5 preparations from rat liver (trypsin solubilized or detergent solubilized) and pig liver (trypsin solubilized). The results presented establish that soluble methemoglobin reductase and cytochrome b5 of human erythrocytes are immunochemically similar to NADH-cytochrome b5 reductase and cytochrome b5 of liver microsomes, respectively.
UR - http://www.scopus.com/inward/record.url?scp=0017279859&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0017279859&partnerID=8YFLogxK
U2 - 10.1016/0003-9861(76)90113-2
DO - 10.1016/0003-9861(76)90113-2
M3 - Article
C2 - 1259422
AN - SCOPUS:0017279859
VL - 172
SP - 600
EP - 607
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 2
ER -