Chonnam Med J.  1998 Jun;34(1):87-95.

Purification of a New Antioxidnat Protein from the Hypoxia-Exposed Rat Lung

• Jung YD
• Chay KO
• Song DU
• Song H
• Yang SY
• Lee MW
• Ahn BW

Abstract

Hyperoxia enhances antioxidant potential in rat lung tissues. In this study, an antioxidant protein with Mr of -68 kDa has been purified to nearly homogeneity from the rat lung after animals were exposed to >95% oxygen for 3 days. Purification steps included a DEAE-cellulose chromatography followed sequencially by high pressure liquid chorcatography on DEAE, phenyl, and 300SW gel filtration columns. The approximate molecular wieght of this purified protein as determined by HPLC gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was 68 kDa. This antioxidant protein was found to share the following properties with serum albumin: molecular weight (68 kDa), isoelectric point (pI=-4.65), and reactivity with polyclonal antibodies aganist this 68 kDa protein. However, the specific antioxidant activity of this purified protein was much higher than that of serum albumin. Monoclonal antibodies which preferentially bind to this 68 kDa protein reacted poorly with serum albumin. On treatment with charcoal or 40% ethanol at pH 4.8, the 68 kDa protein lost not only its antioxidant activity but also the reactivity with monoclonal antibodies. These results suggest that the purified antioxidant protein is an albumin derivative in which certain unidentified small molecule(s) is (are) bound to albumin molecule.

Keyword

hyperoxia; antioxidant; albumin

MeSH Terms

Animals
Antibodies
Antibodies, Monoclonal
Charcoal
Chromatography, DEAE-Cellulose
Chromatography, Gel
Chromatography, High Pressure Liquid
Electrophoresis
Ethanol
Hydrogen-Ion Concentration
Hyperoxia
Isoelectric Point
Lung*
Molecular Weight
Oxygen
Rats*
Serum Albumin
Sodium
Staphylococcal Protein A
Antibodies
Antibodies, Monoclonal
Charcoal
Ethanol
Oxygen
Serum Albumin
Sodium
Staphylococcal Protein A