Question

Building on Dr. Allisons work on Sickle Cell anemia Dr. Pauling tested hemoglobin from diseased individuals, normal individuals and heterozygotes using ____________ technique.

Answer 1

Building on Dr. Allisons work on Sickle Cell anemia, Dr. Pauling tested hemoglobin from diseased individuals, normal individuals and heterozygotes using ELECTROPHORESIS technique.

Sickle cell Anaemia is the first genetic disease studied at molecular level. Allison proposed that improved survival among carriers of the mutation (HbAS) in the face of Plasmodium falciparum exposure might confer an evolutionary advantage that could compensate for the early death of the individuals affected by Sickle Cell Anaemia (HbSS) . This is referred to as Malarial hypothesis. Allison and Livingstone were first to study the sickle cell mutation.

Linus Pauling worked very extensively on Haemoglobin. He identified two different forms of haemoglobin present in the people suffering from Sickle cell Anaemia. Pauling Tested the Haemoglobin samples by taking blood samples from different individuals both healthy and with Sickle cell Anaemia using Electrophoresis technique.

Electrophoresis is the technique which seperates the proteins based on the particle size and charge. Using this, he identified that normal people have a regular type of haemoglobin while Subject with sickle cell anaemia has two different types of haemoglobin. This made to identify the change in protein structure. Electrophoresis refers to the movement of ions or charged species in the influence of an electric field. Basically it is a seperation technique based on electrical driven forces. The analytes are seperated based on their different electrophoretic mobility under applied voltage.

Haemoglobin:

Human Haemoglobin present in the erythrocytes has a combination if one pair of alpha chain and another beta chain. Each of these chains has a heme prosthetic group, a tetrapyrrole ring with a central ferrous atom binding to a oxygen molecule reversibly. Haemoglobin is responsible for the transport of oxygen from lungs to the tissues and to take carbondioxide back to lungs.

Sickle Cell Anaemia:

Sickle cell disease is the hereditary disease as a result of abnormal haemoglobin and differs from one individual to the other. The normal Haemogloin , HbA is replaced with HbS. The sickle haemoglobin injures the red cell causing its membrane injury and producing population of heterogenous red blood cells , haemolysis and reduced nitric oxide availability. With the vascular inflammation and oxidative stress the contact between sickle red cells and leukocytes with the endothelium prolong the transit of the red cells through hypoxic vascular beds causing red cell sickling and vaso occlusive processes.