Juan Guevara

Research Associate Professor Juan Guevara
Ph.D. Oregon State University, Biochem/Enz,1977
Office: SETB 1.208
Lab: SETB 1.208
Phone: 956-882-6773
Email: juan.guevara@utrgv.edu


PHYS 3306 01 - Intro to Biophysics


The principle focus of our research is on elucidation of functional regions in the apolipoprotein B100, a massive molecule composed of 4536 amino acids that is the defining protein of the low density lipoprotein particles (LDL). These lipid-loaded particles are known as the “Bad Cholesterol”; however, we discovered that LDL and related lipoparticles have the capacity to bind genetic material and deliver it to the cell nucleus. This capacity was demonstrated using different cell types in culture and in vivo in a rat model. Our lab has identified several regions in apo B100 that provide these particles with signal transduction, nucleic acid binding, receptor binding, cell entry, and nuclear translocation capacity. Some of these structural domains were identified based on their similarity to proteins of the Flaviviruses, such as Dengue, and to Interferon Regulatory Factors of the human immune response. Fluorescence-labeled synthetic peptides were then used in cell culture to confirm their function. This experimental path has led to the creation of a submicron resolution optical microscopy system that allow study and capture of live cell activities. This system provides us the capacity to resolve the canopy of cell surface proteins and to monitor dynamic activity on the cell surface and in the cytoplasm. Although our purpose was to track labeled LDL/DNA particles through to the nucleus to determine point of separation of protein from nucleic, it became evident that our system can be used to study the ectodomain properties of different cell types and changes that may occur due to infection and/or malignancy.