Electron transport chain amino acid structure

In these mechanisms, electron transport through the various components of the electron-transport chain leads to structural changes in the proteins of the chain, such that changes in their pKa values (Chap. 3) of ionizable amino acid residues occurs. For example, an increase in the pKa of a residue adjacent to the matrix side of the membrane would lead to proton uptake from the matrix, while a decrease in the pKa of a residue adjacent to the intermembranous side of the membrane could lead to release of a proton. The net effect of these processes is the transfer of protons from the matrix to the intermembranous side of the membrane. However, proton-pump mechanisms do not make strong predictions of the H+/e stoichiometries. 

Mycotoxin from cultures of different Fusarium species, e.g., F. sambucimm and F. oxysporum C28H39NO4, Mr 453.62, prisms, mp. 197 C, [a] -200 (CH3OH). S. inhibits electron transport (complex III) in isolated mitochondria and is structurally related to funiculosin. It shows antifungal activity. S. is of mixed biosynthetic origin (polyketide chain and aromatic amino acid), see tenellin. 

Due to the central role of DNA and proteins in biochemistry and biophysics the computation of the electronic structure of periodic polymers built from nucleotide bases, base pairs, nucleotides and amino acids, respectively, had been of high interest since about twenty years. Early calculations of the band structure of DNA related periodic polymers have been performed with the crystal orbital (CO) method on the basis of different semiempirical levels (1). Recently the results of ab initio Hartree-Fock CO (2, 3) band structure calculations for the four nucleotide base stacks (4-6), the two Watson-Crick base pair stacks (6), the sugar-phosphate chain (4,5) and the three nucleotides cytidine (4,5), adenylic acid and th3nnidine (6) have been reported. These computations represent a significant progress but the following improvements are required for a more accurate description of the electronic structure of real DNA and its transport properties ... 

---