Secondary Structures Associated With Alkaline Transition of Horse Heart Ferricytochrome C: An FTIR Study

Abstract

ABSTRACT:The spectra of amide I region (1700-1600cm -1 ) of horse heart ferricytochrome c at 20 o C are reported at low ionic strength at of pH values between 7.0 and 11.5 encompassing the alkaline transition. The mid-infrared spectra can probe the protein secondary structures. The Fourier transform infrared spectroscopic technique is used to investigate the changes in the conformationally sensitive amide I band of cytochrome c with pH and ionic strength. Analysis of these results supports the hypothesis that an increase in the non-repetitive secondary structure during alkaline transition is at the expense of regular secondary structures. These strongly suggest that structural switching and ligand exchange behaviour of ferricytochrome c is accompanied by conformational change in the protein backbone.

Biomolecules, Fatty Acids, Meat Quality, and Growth Performance of Slow-Growing Chickens in an Organic Raising System

“…It has been shown that FA from the diet strongly influences the amount of FA in meat [ 71 ]. Similarly, grass intake has been shown to increase antioxidants content in plasma and consequently decrease FA oxidation [ 45 ]. In addition, fresh grass contains 50–75% ALA [ 72 ], a precursor of long-chain n-3 PUFA.…”

“…The relative integral areas were calculated from the second derivative spectra in the spectral region from 3000 to 900 cm −1 as follows: 3000 to 2800 cm −1 (CH stretching of lipid), 1740 cm −1 (C=O ester of lipid), 1700 to 1600 cm −1 (amide I), 1600 to 1500 cm −1 (amide II), 1338 cm −1 (amide III), and 1250 to 900 cm −1 (carbohydrate and glycogen) using OPUS software (version 7.2, Bruker Optics Ltd.), as shown in Table 2. to 1600 C=O stretching Amide I band of proteins [41] 1655, 1650 to 1640 C=O stretching Amide I of α-helical structures of proteins [42,43] to 1685 C=O stretching Antiparallel β-sheet [41] to 1520 C-N stretching + N-H bending coupled in of face Amide II band of proteins [43] to 1240 C-N stretching + N-H bending coupled in of face Amide III of proteins [40,43] to 1615 C=O stretching β-sheet [40,43,44] to 1664 to 1675 C=O stretching β-turn [44,45] 1200 to 900…”