J. Stenflo coauthored the 1974 work identifying gamma-carboxyglutamic acid in prothrombin, connecting Vitamin K dependence with a specific chemical modification of a clotting protein. The study isolated a four-residue peptide from the calcium-binding amino-terminal region and found mobility that ordinary amino-acid composition did not explain.[ref]
Nuclear magnetic resonance and mass spectrometry identified two modified glutamic-acid residues in that peptide. The result supplied a chemical identity for the anomaly, rather than treating an altered migration pattern alone as a complete explanation.[ref]
Vitamin K dependent modifications of glutamic acid residues in prothrombin by J. Stenflo and others. Abstract: proton NMR, mass spectrometry and two gamma-carboxyglutamic-acid residues
An additional carboxyl group changes a side chain's chemical possibilities, including its interactions with ions. This makes post-synthesis chemistry biologically significant: two protein preparations with the same genetically specified sequence can differ in modifications and function. The finding helped connect a nutritional requirement, a measurable molecular difference and the behavior of a calcium-binding protein, while preserving the distinction between a chemical observation and a physiological inference.
Articles by others on the same topic
There are currently no matching articles.