UCLA-DOE Institute Proteomics Research Highlighted in Chemical & Engineering News

Summary

Research directed by Dr. Joseph A. Loo in the UCLA-DOE Institute for Genomics and Proteomics is studying protein machines in Methanosarcina species, a group of microbes that generate methane. Most functions of living cells are carried out by macromolecular machines that contain ten or more protein molecules. Characterizing the structure of these complexes is a key to understanding their functions, and mass spectrometry is becoming a preferred technique for identifying how protein machines are organized. Dr. Loo’s research on the proteasome of Methanosarcina thermophila is highlighted in the September 29, 2003, issue of Chemical & Engineering News as part of a report on the 16th International Mass Spectrometry Conference just held in Edinburgh, Scotland. The proteasome contains 28 protein molecules and breaks down proteins that are defective or no longer needed by the cell, serving, as Loo puts it, as the cellular “garbage disposal.” His mass spectrometric studies have identified binding of inhibitor molecules to the proteasome and have determined how stepwise breakdown of the proteasome results in loss of the inhibitor molecules. Other protein complexes are also being characterized by Loo, including a complex of ribonucleic acid (RNA) and proteins that is known as “vault” and has a mass of 13 million Daltons.