Mechanical Instability of the Oxy-form of Sickle Haemoglobin

• Published in: Nature (London) 1973-08, Vol.244 (5416), p.437-438
• Main Authors: ASAKURA, T., AGARWAL, P. L., RELMAN, D. A., MCCRAY, J. A., CHANCE, B., SCHWARTZ, E., FRIEDMAN, S., LUBIN, B.
• Format: Article
• Language: English
• Subjects: Hemoglobin, Sickle; Hemoglobins, Abnormal; Humanities and Social Sciences; Humans; Hydrogen-Ion Concentration; letter; multidisciplinary; Oxygen; Protein Denaturation; Science; Science (multidisciplinary); Spectrophotometry; Temperature; Ultrasonics
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/244437a0

MUCH attention has been given to the molecular aspects of the deoxy form of sickle haemoglobin (Hb S) because sickling occurs with Hb S in the deoxygenated state. The oxy form of Hb S, on the other hand, is believed to be similar to normal adult haemoglobin (Hb A) with respect to solubility 1,2 , X-ray diffraction pattern 3 , oxygen binding 4 and other properties. During determination of oxygen equilibrium curves of Hb S, we noticed that a solution of oxyhaemoglobin S became turbid very easily when it was stirred or mixed. The turbidity was found to be due to protein which was denatured by the mechanical force involved and/or by foaming. Oxyhaemoglobin S denatured more quickly than oxyhaemoglobin A by mixing, stirring or sonication. The rate of denaturation was dependent on the oxygen concentration in the medium, suggesting that an oxidative process was involved. As demonstration of denaturation requires only a few drops of blood, water and shaking, this property can be used as a simple clinical test for the presence of Hb S.