Characteristics of Adult and Foetal Myoglobin in the Visible Light Spectrums

Abstract

A MYOGLOBIN which differed from adult myoglobin (MbA) was found in the urine¹ of a 28-year-old woman during an episode of idiopathic rhabdomyolysis with myoglobinuria. The same haem protein was later demonstrated in the patient's skeletal muscle² where it comprised the bulk of the benzidine positive protein after haemoglobin and cytochrome c had been separated from the myoglobin by column chromatography. This distinct chromoprotein was similar in its solubility in ammonium sulphate, spectroscopic characteristics and on cellulose acetate electrophoresis to foetal skeletal myoglobin (MbF) prepared in the same manner from the psoas muscle of infants stillborn at term. It was concluded that myoglobin, like haemoglobin, can present molecular variations which express themselves as disease syndromes, for example, rhabdomyolysis, under certain conditions. Although these clinical and biochemical findings have been supported by one investigator³, other reports do not regard MbF as an entity but rather as an artefact produced by the method used in preparing the myoglobin for analysis. The evidence against MbF has recently been summarized⁴. The present report examines the spectroscopic characteristics of MbA and MbF, adult and foetal haemoglobin (HbA and HbF, respectively) derived from muscle and blood of the human, dog and pig. The methods were designed to study the various pigments under optimum and standard conditions to minimize the effects of changing pH, salt concentrations, temperature, state of haem oxidation, crystallizations and other manipulations.