Orientation of Sickled Erythrocytes in a Magnetic Field

Abstract

A HYPOTHESIS of a molecular mechanism of sickled erythrocyte formation was presented in a previous communication¹. It was based on an earlier observation² that the de-oxygenated sickle cell haemolysate forms a gel at 38° but, contrary to our usual experience, it ‘melts’ (or liquefies) on cooling to 0°. Afterwards, the problem was investigated further by means of optical rotatory dispersion investigations at 0° and 38°; it was concluded that at 38° the amino-terminal valyl residue interlocks with the genetically interchanged valyl residue at position 6 in the β-chain, allowing cyclization from carbonyl of the first valyl to the NH of the fourth threonyl by hydrogen bonding. Interaction between the two valyl side-chain residues is due to hydrophobic bonding (Fig. 1, ref. 1). If this hypothesis is correct, then a simple hydrophobic molecule such as propane, which is similar in structure to the valyl side-chain residue, could ‘melt’ the gel of the sickle cell haemolysate at 38° by a process of transferring the hydrophobic bonds. It was found experimentally that propane, ethane and methane can ‘melt’ the gel; these alkane gases can also ‘unsickle’ sickled erythrocytes¹.