University of Wisconsin Stevens Point, Biochemsitry, Stevens Point, WI 54481
The role of Pregnancy Associated Plasma Protein–A (PAPP-A) as a protease was discovered in 1999 because it was found to specifically cleave the Insulin-like Growth Factor Binding Protein-4 (IGFBP-4). Additionally, PAPP-A has been found to be involved in different biological systems such as wound healing, cancer, fetal development, and atherosclerosis. Because PAPP-A is involved in so many diverse biological systems, an experiment was designed to determine if PAPP-A was able to cleave proteins other than IGFBP-4. The easiest way to find proteins that PAPP-A cleaves would be to compare protein expression between a sample with PAPP-A present and a sample with PAPP-A lacking. Any protein expression differences found would likely be due to PAPP-A activity. An experiment was designed to compare mice embryos that had the PAPP-A gene knocked out (these mice do not have PAPP-A expression or activity) and mice embryos that are wild-type for the gene PAPP-A (these mice have normal PAPP-A expression and activity). The mice embryos were all same sex littermates, which is important for comparison purposes because the protein expression differences will be less likely due to other genetic and/or sex differences and more likely due to the presence or lack of PAPP-A. The proteins from the mice embryos were extracted, and then underwent 2-Dimensional (2-D) Gel Electrophoresis, which first separates proteins by their isoelectric point and then by their molecular weight. A comparison of the protein expression on the 2-D gels will be done to identify protein expression differences between the PAPP-A wild-type mice embryos and the PAPP-A knockout mice embryos.
[Abstract (DOC)]