Since the beginning of my scientific career I have worked at the interface of chemistry and biology using biophysical tools. My undergraduate research experiences in protein chemistry and biophysics at my home institution, the University of Puerto Rico, Cayey as well as summer research at the University of North Carolina, Chapel Hill inspired me to pursue an interdisciplinary approach to scientific questions leading me to graduate school at the University of Massachusetts, Amherst in the molecular and cellular biology program.
My graduate thesis explored the structure and function of lysosomal enzymes. I determined the X-ray crystal structures of two lysosomal sulfatases (SGSH and GALNS) and analyzed the mutations that lead to their respective diseases, MPS III A and MPS IV A. This analysis revealed that these diseases could reflect protein misfolding since the majority of the mutations are located in the hydrophobic core of the proteins. The active site pockets of these enzymes have features such as charged amino acids and hydrophobic amino acids suitable for structure-based drug design. I also determined that the small molecules galactose, 1-deoxygalactonojirimycin (DGJ) and 4-epi-isofagomine are competitive inhibitors of GLB1. Using the published crystal structure of GLB1, I presented an explanation for the inhibitory effects of 4-epi-isofagomine.
After completing my doctoral work, I sought further research experience that would allow me the opportunity to also teach undergraduate students. I was fortunate to receive the PENN-Postdoctoral Opportunities in Research and Teaching fellowship. My current research projects are focused on understanding the molecular basis for acetylation by both an N-terminal acetyltransferase (NatA) and the cohesin acetyltransferases (ESCO1 and ESCO2). The latter project was a collaborative effort with an undergraduate student and led to a recently submitted manuscript.
Based on my previous research experiences, I have developed a research program composed of innovative, accessible and fundable projects. These projects are suitable for research with undergraduates from diverse science majors. Given my training, I am in a position to integrate different points of view including protein structure, function and chemistry as well as molecular biology to answer central questions in protein design and evolution of acetyltransferases, which govern many cellular processes. The Rivera lab will focus on understanding acetyltransferases enzymatic mechanism as well as the evolutionary question of what protein features are necessary for acetylation.