Modifications of hemoglobin and myoglobin by Maillard reaction products (MRPs)
Journal
PLoS ONE
Date Issued
November 2017
Author(s)
DOI
10.1371/journal.pone.0188095
Abstract
High performance liquid chromatography (HPLC) coupled with a Fraction Collector was
employed to isolate Maillard reaction products (MRPs) formed in model systems comprising
of asparagine and monosaccharides in the 60–180˚C range. The primary MRP which is
detected at 60˚C is important for Acrylamide content and color/aroma development in foods
and also in the field of food biotechnology for controlling the extent of the Maillard reaction
with temperature. The discrete fractions of the reaction products were reacted with Hemoglobin
(Hb) and Myoglobin (Mb) at physiological conditions and the reaction adducts were
monitored by UV-vis and Attenuated Total Reflection-Fourier transform infrared (FTIR)
spectrophotometry. The UV-vis kinetic profiles revealed the formation of a Soret transition
characteristic of a low-spin six-coordinated species and the ATR-FTIR spectrum of the HbMRP
and Mb-MRP fractions showed modifications in the protein Amide I and II vibrations.
The UV-vis and the FTIR spectra of the Hb-MRPs indicate that the six-coordinated species
is a hemichrome in which the distal E7 Histidine is coordinated to the heme Fe and blocks
irreversibly the ligand binding site. Although the Mb-MRPs complex is a six-coordinated species,
the 1608 cm-1 FTIR band characteristic of a hemichrome was not observed.
employed to isolate Maillard reaction products (MRPs) formed in model systems comprising
of asparagine and monosaccharides in the 60–180˚C range. The primary MRP which is
detected at 60˚C is important for Acrylamide content and color/aroma development in foods
and also in the field of food biotechnology for controlling the extent of the Maillard reaction
with temperature. The discrete fractions of the reaction products were reacted with Hemoglobin
(Hb) and Myoglobin (Mb) at physiological conditions and the reaction adducts were
monitored by UV-vis and Attenuated Total Reflection-Fourier transform infrared (FTIR)
spectrophotometry. The UV-vis kinetic profiles revealed the formation of a Soret transition
characteristic of a low-spin six-coordinated species and the ATR-FTIR spectrum of the HbMRP
and Mb-MRP fractions showed modifications in the protein Amide I and II vibrations.
The UV-vis and the FTIR spectra of the Hb-MRPs indicate that the six-coordinated species
is a hemichrome in which the distal E7 Histidine is coordinated to the heme Fe and blocks
irreversibly the ligand binding site. Although the Mb-MRPs complex is a six-coordinated species,
the 1608 cm-1 FTIR band characteristic of a hemichrome was not observed.
File(s)![Thumbnail Image]()
Name
journal.pone.0188095.pdf
Size
7.8 MB
Format
Adobe PDF
Checksum (MD5)
2229b50ad2be5dfa58aeaea7eb4f85c8