The impacts of some environmental pollutants and exogenous toxic ligands on conformational and functional properties of human hemoglobin: A systematic review of spectroscopic literature

The objective of the present study was to collect the spectroscopic results obtained from previous studies to determine how exogenous toxic ligands can alter the structural and functional properties of human hemoglobin (HHb).

Using spectroscopic techniques, English published articles (from January 2009 to June 2020) on HHb were systematical reviewed by searching several databases such as PubMed, ScienceDirect databases, and Google Scholar. In this regard, some keywords were searched, including (human hemoglobin) AND (spectroscopy) OR (spectroscopic analysis) OR (spectroscopic studies) AND (environmental pollutants) OR (food additives) OR (dyes) OR (fuel additives) OR (radioactive metal ions) OR (insecticides) OR (food colorants). After screening full text articles, we extracted relevant data according to our subject from included articles.

Finally, 17 studies were found to be related to the subject of this study. Analysis of investigations suggested that after exposure of HHb to each exogenous ligand, we could observe heme hydrophobic pocket alteration, fluorescence quenching, and polarity alteration around aromatic residues of protein, indicating that the structural properties of HHb were changing. Lack of some spectroscopic techniques in some articles could place some minor limitations on the obtained evidence.

Considering the impacts of the exogenous ligands on characteristics of HHb, in the first step, it is the responsibility of governments to exercise strict control over the manufacturing sectors and then industry owners to investigate the effects of chemical products on the living organisms before commercializing them.