"Drug Discovery and Development as Seen Through the Eyes of an Analytical Chemist"
Dr. Kevin Bateman, Distinguished Scientist at Merck
"Global Analysis of Breast Cancer-Related Conformational Changes in Proteins"
Fang Liu, Laboratory of Professor Michael Fitzgerald, Duke University, Department of Chemistry
Conformational changes in proteins can lead to disease. Thus, methods for identifying conformational changes in proteins can further improve our understanding and facilitate detection of disease states. Here, we utilize stable isotope labeling with amino acids in cell culture in combination with limited proteolysis (LiP) under native conditions to characterize breast cancer-related conformational changes in proteins on the proteomic scale. Two cell culture models of breast cancer including the MCF-10A and MCF-7 cell lines were used for the study. The LiP approach described here identified ∼200 protein hits with cell line dependent conformational changes. A bioinformatics analysis revealed that nucleic acid binding proteins represented the largest fraction of the protein hits. Interestingly, over two-thirds of the protein hits identified with conformational differences between the two cell lines did not have significant (i.e., less than 2-fold) changes in their expression levels. This suggests that conformational changes can provide information about disease states that is orthogonal to that obtained in protein expression level analyses. The two cell lines studied here were recently characterized by the Stability of Proteins from Rates of Oxidation (SPROX) technique to profile the differential chemical denaturant-induced equilibrium unfolding properties of the proteins in these cell lines. The LiP protein hits reported here will also be discussed in the context of the previously reported SPROX protein hits.