Honors Program

Spring Showcase Presenters

Hallel Paraiso

Title: “A Novel Integration Method For Inserting Portal Proteins Into Planar Bilayer Membranes”
Major: Biology
Faculty Mentor:  Dr. Peng Jing (Chemistry)

My name is Hallel Paraiso, and I am a senior here at IPFW majoring in Biology. You may wonder, “Why are you in a chemistry research lab then?” The answer to that is quite simple: The research that Dr. Jing is involved with is based on biological membranes, but we use chemistry to analyze the proteins. I have been working in his lab for nearly two years, and I do not regret a single moment of being in the lab. I have learned so much doing research, whether it pertained to a deeper understanding of biology and chemistry or simply presenting my work to faculty members. The research I worked on dealt with analyzing the efficiency of inserting portal proteins into a biological membrane. By testing different variables with the help of computer softwares and devices, I can get a visual summarization of the data that helps me determine if the data proves or disproves the hypothesis. My experience here has been phenomenal, and I look forward to seeing the results of this wonderful research!

Abstract

Channel proteins serve a pivotal role in transporting specific substrates and molecules across a plasma membrane (Schwartz, et al., 1997). For this reason, much research has been devoted to developing methods on how to use these channel proteins as biomolecular sensors. However, the sensor must be specific to the size of substrate. For example, portal proteins are found in bacteriophages and are responsible for transferring DNA from a virally-infected bacteria to the bacterial capsid during the lytic phase of the viral cycle. For this reason, the portal protein GP10 (from the bacteriophage phi29) was joined with a liposome to form a proteoliposome, which was then inserted into a planar bilayer  membrane for studying DNA packaging mechanisms (Wendell, et al., 2009). However, the results are highly variable due to the fact that the procedures used to achieve a stable and consistent platform are very arduous, time-consuming, and different from person to person.

This research focuses on overcoming such challenges by modifying the procedures to prepare the proteoliposomes. Instead of utilizing detergent, which is a time-consuming step and can cause protein aggregation, glycerol was utilized, thus eliminating these two potential problems. The results of applying glycerol to the mutant portal protein GP20 (from T4 bacteriophage), show a more efficient and rapid fusion of the channel proteins into the planar bilayer membrane. Furthermore, the use of glycerol increases the shelf life of the proteoliposome four-fold (Jing, Paraiso, & Burris, A Rapid, Effective, and Universal Method for Inserting Portal Proteins from Bacteriophages into Planar Bilayer Membranes).

The implications of this research leads to the conclusion that this method can be used to form proteoliposomes from any portal proteins. Therefore, studies on the structural functions of unknown portal proteins can be done, thereby shedding light on how DNA or other macromolecules are translocated across a plasma membrane. Moreover, this technology has the potential to be used as a cheaper alternative for  determining unknown DNA sequences.