The Department of Genetic Medicine at Weill Cornell leads a dynamic and innovative translational research program, advancing diverse fields such as Genetic Therapy and Personalized Medicine.
Our translational research program aims to leverage our expertise in genetic therapies and personalized medicine to develop clinical solutions that target the molecular causes of human diseases.
The Department of Genetic Medicine advances treatments and diagnostics through diverse clinical trials, including drug testing and research to better understand diseases.
The Department of Genetic Medicine at Weill Cornell leads a dynamic and innovative translational research program, advancing diverse fields such as Genetic Therapy and Personalized Medicine.
Our translational research program aims to leverage our expertise in genetic therapies and personalized medicine to develop clinical solutions that target the molecular causes of human diseases.
The Department of Genetic Medicine advances treatments and diagnostics through diverse clinical trials, including drug testing and research to better understand diseases.
Chemical approaches to the study of protein tyrosine kinases and their implications for mechanism and inhibitor design.
Publication Type
Review
Authors
Cole P, Sondhi D, Kim K
Journal
Pharmacol Ther
Volume
82
Issue
2-3
Pagination
219-29
Date Published
01/01/1999
ISSN
0163-7258
Keywords
Chemistry, Pharmaceutical, Lymphocyte Specific Protein Tyrosine Kinase p56(lck), Protein Kinases, Proteins
Abstract
Protein tyrosine kinases are critical enzymes for signal transduction. Using C-terminal Src kinase (Csk) as a model system, we discuss progress in three main areas. First, we describe our efforts to measure the transition state of the reaction using peptide substrates containing fluorotyrosine analogs. It is shown that the Brønsted nucleophile coefficient for the reaction is near zero (similar to the nonenzymatic reaction) and the required nucleophile is the neutral phenol (rather than the more chemically reactive phenoxide anion). By studying the kinase reaction in the reverse direction, a Brønsted leaving group coefficient of -0.3 was measured, indicative of protonation of the departing phenol in the transition state. Taken together, these results strongly support a dissociative transition state mechanism for the kinase. These findings set constraints on the design of transition state analog inhibitors. Second, we describe efforts toward defining the specificity of Csk for peptide and protein substrates. The main findings are that local amino acids surrounding a phosphorylated tyrosine can influence recognition, but that long-range interactions probably are more important in a physiologic protein substrate. These findings underscore the complexities in how protein kinases select protein substrates. Third, we describe a new method in protein engineering that has been applied to the study of protein kinases. The method, expressed protein ligation, allows a general approach for ligating synthetic peptides to recombinant proteins. Using expressed protein ligation, obtaining site-specifically phosphorylated proteins and proteins with the incorporation of biophysical probes becomes relatively straightforward. We have used this method to generate a tail phosphorylated, conformationally altered Csk that showed an unexpected increase in kinase activity.