47 questions · 29 almanac · 0 findings

Protein Structure

The three-dimensional architecture of proteins.

Almanac Weighing a Single Protein by How Fast It Sinks
  • How does an ultracentrifuge use spinning force to reveal the mass of a single protein molecule?
  • Why did chemists before Svedberg struggle to determine whether proteins were discrete molecules or fuzzy colloidal clouds?
Almanac Blood and Leaf, Close Cousins
  • What is haemin and why does it sit at the core of the haemoglobin molecule?
  • How are haemoglobin and chlorophyll molecular cousins, and what actually differs between them?
Almanac Serum Was Never Just One Thing
  • How does moving-boundary electrophoresis separate proteins that look identical in solution?
  • What later fields of science and industry grew out of Tiselius's separation method?
Almanac Insulin, Read Letter by Letter
  • What technique did Sanger use to label the terminal ends of protein fragments during sequencing?
  • Why did Sanger's decade-long sequencing of insulin overturn the assumption that proteins had irregular, variable composition?
Almanac Not Ropes After All
  • Why did scientists originally assume proteins were simple, repetitive structures before Kendrew and Perutz's work?
  • How does X-ray crystallography reveal the atomic structure of something as large and irregular as a protein?
  • What shape did myoglobin turn out to have, and how does that shape let it hold and release oxygen?
  • How is hemoglobin's structure related to myoglobin's, given that hemoglobin carries oxygen in blood rather than muscle?
Almanac Twenty-Two Years to See One Molecule
  • What was the 'phase problem' in X-ray crystallography, and how did attaching heavy atoms like mercury solve it?
  • Why did Kendrew's myoglobin structure get solved before Perutz's haemoglobin, despite being the same underlying method?
Almanac The Cell Had Postal Codes All Along
  • What are signal sequences, and how do they direct a newly made protein to its correct cellular compartment?
  • How did Günter Blobel demonstrate that proteins carry built-in address labels?
Almanac A Molecular Label That Reads 'Destroy This'
  • How does ubiquitin tag proteins for destruction inside a cell?
  • What role does the proteasome play in breaking down tagged proteins?
  • Which diseases are linked to disruption of the ubiquitin-proteasome pathway?
Almanac Weighing a Protein Without Killing It
  • Why did traditional mass spectrometry destroy proteins before they could be measured?
  • How did Kurt Wüthrich use nuclear magnetic resonance to determine protein structure in solution?
Almanac A Luggage Tag for Doomed Proteins
  • How does ubiquitin mark a protein for destruction inside a cell?
  • What role does the proteasome play once a protein has been tagged with ubiquitin?
  • Why is ubiquitin's near-universal presence in eukaryotic cells significant?
  • How are defects in ubiquitin pathways connected to diseases like Parkinson's and cancer?
Almanac Persuading an Egg to Reconsider
  • What happens to egg-white proteins during denaturation?
  • How does a vortex fluidic device use shear force to refold proteins?
  • Why is reversing protein denaturation relevant to diseases like Alzheimer's?
Almanac Fifty Years, Then a Machine Learned the Shape
  • How does AlphaFold2 predict a protein's structure directly from its sequence, and how accurate is it compared to experimental methods?
  • What does it mean for David Baker to design proteins that 'do not exist in nature', and what are these novel proteins used for?