CHAPTER 24 – Evolution of Protein Molecules

Inference of macromolecular assemblies from crystalline state.

On the Nature of Allosteric Transitions: A Plausible Model

Solvent content of protein crystals.

Stanford Moore, William Stein, and Anfinsen were awarded the Nobel Prize in Chemistry in 1972 for \"their contribution\n to the understanding of the connection between chemical structure and catalytic activity of the active center of the ribonuclease\n molecule.\" In his Nobel Lecture, Anfinsen provided a sketch of the rich history of research that provided the foundation\n for his work on protein folding and the \"Thermodynamic Hypothesis,\" and outlined potential avenues of current and\n future scientific exploration.

https://web.iitd.ac.in/~amittal/1973_Anfinsen_Science.pdf

Principles that Govern the Folding of Protein Chains

The oxygenation of haemoglobin is accompanied by structural changes in the subunits triggered by shifts of the iron atoms relative to the porphyrin and, in the β-subunits, also by the steric effect of oxygen itself. The oxygen-free form is constrained by salt-bridges which are broken by the energy of haem–haem interaction with the release of H+. 2,3-Diphosphoglycerate may add to the constraints by being stereochemically complementary to a site between the β-chains ; this complementarity is lost on oxygenation.

Stereochemistry of cooperative effects in haemoglobin.

Structure of Hæmoglobin: A Three-Dimensional Fourier Synthesis at 5.5-Å. Resolution, Obtained by X-Ray Analysis

Four inherited neurodegenerative diseases are linked to abnormally expanded repeats of glutamine residues in the affected proteins. Molecular modeling followed by optical, electron, and x-ray diffraction studies of a synthetic poly(L-glutamine) shows that it forms beta-sheets strongly held together by hydrogen bonds. Glutamine repeats may function as polar zippers, for example, by joining specific transcription factors bound to separate DNA segments. Their extension may cause disease either by increased, nonspecific affinity between such factors or by gradual precipitation of the affected proteins in neurons.

https://www.pnas.org/content/pnas/91/12/5355.full.pdf

Glutamine repeats as polar zippers: their possible role in inherited neurodegenerative diseases

The secondary structure of the haemoglobin chains is similar to that of myoglobin, but some of the helical segments are more irregular and some parts of the non-helical segments have different conformations. The structure of the contacts between unlike subunits suggests that the tetramer, rather than the αβ dimer, is the functional unit of haemoglobin.

Three-dimensional Fourier Synthesis of Horse Oxyhaemoglobin at 2.8 Å Resolution: The Atomic Model

http://web.stanford.edu/class/sbio228/public/readings/Introduction_Lecture1/Levitt_JMB_88_Aromatic_Hbond.pdf

Max F. Perutz

Papers

Stereochemistry of cooperative effects in haemoglobin.

Structure of Hæmoglobin: A Three-Dimensional Fourier Synthesis at 5.5-Å. Resolution, Obtained by X-Ray Analysis

Glutamine repeats as polar zippers: their possible role in inherited neurodegenerative diseases

Three-dimensional Fourier Synthesis of Horse Oxyhaemoglobin at 2.8 Å Resolution: The Atomic Model

Aromatic rings act as hydrogen bond acceptors