Aldose and aldehyde reductases in human tissues

Area of Science:

• Biochemistry
• Enzymology
• Immunochemistry

Background:

• Aldose reductase and aldehyde reductases are enzymes involved in cellular metabolism.
• Understanding their immunochemical properties and tissue distribution is crucial for elucidating their physiological roles.
• Previous characterizations were limited, necessitating further investigation into their relationships.

Purpose of the Study:

• To immunochemically characterize human aldose reductase and aldehyde reductases I and II.
• To determine the tissue distribution of these enzymes.
• To propose a model for the genetic interrelationships among these reductases.

Main Methods:

• Partial purification of enzymes using DEAE-cellulose (DE-52) column chromatography.
• Immunotitration using antisera against purified human and bovine aldose reductase and human aldehyde reductases I and II.
• Immunoaffinity purification of monospecific anti-alpha and anti-beta antisera.

Main Results:

• Immunochemical cross-reactivity was observed between anti-aldose antiserum and aldehyde reductase I, and between anti-aldehyde reductase I antiserum and aldose reductase.
• Aldehyde reductase II showed specific precipitation with its antiserum and no cross-reactivity with aldose reductase or aldehyde reductase I.
• Distinct tissue distributions were identified: aldose reductase in aorta, brain, erythrocyte, and muscle; aldehyde reductase I in kidney, liver, and placenta; aldehyde reductase II in brain, erythrocyte, kidney, liver, lung, and placenta.
• Anti-alpha antiserum precipitated both aldehyde reductase I and aldose reductase, while anti-beta antibodies reacted only with aldehyde reductase I.

Conclusions:

• A three gene loci model is proposed based on subunit composition and genetic interrelationships.
• Aldose reductase is a monomer of alpha subunits.
• Aldehyde reductase I is a dimer of alpha and beta subunits.
• Aldehyde reductase II is a monomer of delta subunits.