MYOGLOBIN vs. HEMOGLOBIN BLOCKADE MODEL RELATED SMOKE GAS INHALATION - A COMPUTATIONAL ANALYSIS

Abstract

To identify the pattern of myoglobin compared to hemoglobin blockade by the combustion products contained in the fire smoke using computational chemistry tools. The myoglobin unavailability can be a determining factor of the severity and consequences of smoke poisoning, generating the inability of patients to attempt evacuate themselves, compromising myocardial function, leading to crush syndrome-like effects and increasing of multi-organ failure to the victims of mass burn casualties event. In this study, it was used quantum chemical calculations performed with the Gaussian program suite using DFT/B3LYP/6-311G level of theory to optimize molecular geometries, calculate the molecular electrostatic potential, and obtain the vibrational spectrum. These calculations were applied to the myoglobin and hemoglobin model, thus studying their binding to the essential components of toxic fire smoke. Comparing the structural descriptors – frontier molecular orbitals, energy difference, electric dipole moment (μ), was obtained the highest values as belonging to hydrogen cyanide (2.9), which may explain its increased reactivity, meaning strong interaction with both myoglobin and hemoglobin, followed by hydrochloric acid (1.03) and carbon monoxide (0.122). Within the framework of complex intoxication generated by the inhalation of fire smoke, myoglobin is blocked in a temporal manner and according to a very similar pattern to hemoglobin. It follows that the significant rhabdomyolysis found in these patients is due not only to hypoxemia but also to the primary unavailability of myoglobin, and myocardial damage is also multifactorial. Although slightly discussed, the calculation of different structural and geometric descriptors for hydrochloric acid reveals for hydrochloric acid high values, suggesting binding affinities comparable to those of carbon monoxide. Molecular modeling programs allow for new approaches and can identify parameters or areas of their reference that influence the management of patients intoxicated with fire smoke components.