Polypeptide hydrogen exchange

Native monellin consists of two polypeptide chains, a 45-residue A-chain and a 50-residue B-chain, linked by non-covalent interactions. At neutral pH, it is fairly resistant to heat denaturation with a higher than 80 °C. The crystal structure of native monellin shows a tertiary structure comprising an anti-parallel /1-sheet with five strands and an a-helix. H NMR spectroscopy and hydrogen exchange methods have been used to characterize the alcohol-denaturated state of monellin in order to understand how its secondary structure depends on environmental conditions. " Structural and dynamic studies by NMR have been carried out in order to compare native monellin and a non-sweet analogue in which Asp was replaced by Abu . The three-dimensional structures of the two proteins are found to be very... 

The reader will find many references in this book to spectroscopy done on biochemical substances in aqueous solution. Chapters 6, 10, 11, 12, and 15 on carbohydrates, proteins and polypeptides, hydrogen-deuterium exchange, nucleic acids, and enzymology contain representative discussions of such studies. 

As noted in the timeline, hydrogen exchange in folded polypeptides had been recorded by MS before the work of Zhang and Smith.)... 

An important stage in the OEC model development based on this C-shaped cluster is shown in Pig. 19 [118]. This description established the role of the neutral tyrosyl radical (Yz—O ) derived from the Tyrl61 residue on the D1 polypeptide as the primary oxidant of the Mu4 cluster. In addition, the Yz OH/Yz 0 redox system provides a means of coupling proton transfer to electron transfer during the S-state cycle. It has been argued that these H+/e exchanges are accomplished exclusively by hydrogen atom transfer on... 

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