Rat haemoglobin heterogeneity. Two structurally distinct alpha chains and functional behaviour of selected components

Area of Science:

• Biochemistry
• Animal Physiology
• Molecular Biology

Background:

• Hemoglobin (Hb) heterogeneity in mammals is crucial for oxygen transport.
• Understanding rat hemoglobin composition provides insights into mammalian globin evolution.
• Wistar rats are a common model organism, making their Hb characterization relevant.

Purpose of the Study:

• To characterize the multiple hemoglobin components in adult Wistar rats.
• To analyze the globin chain composition and subunit structure of rat hemoglobins.
• To investigate the oxygen-binding properties and Bohr effect of purified rat hemoglobins.

Main Methods:

• Cellulose acetate electrophoresis and DEAE-cellulose chromatography for Hb separation.
• CM-cellulose chromatography (in formic acid-pyridine and 8M-urea buffers) for globin chain isolation.
• Urea-starch gel electrophoresis for correlating Hb and globin chain identities.

Main Results:

• Six distinct hemoglobin tetramers were resolved.
• Two alpha and three non-alpha globin chains were identified.
• Partial amino acid sequences of alpha chains were determined.
• Purified hemoglobins exhibited similar oxygen affinities, but lower than the unfractionated hemolysate.
• Rat hemoglobins demonstrated a pronounced alkaline Bohr effect.

Conclusions:

• The study successfully characterized rat hemoglobin heterogeneity and subunit composition.
• Rat hemoglobins possess distinct oxygen-binding characteristics and a significant alkaline Bohr effect.
• These findings contribute to the understanding of mammalian hemoglobin function and adaptation.