Understanding the Reduction Potential of Azurin and Type 1 Copper Protiens
Student: Yuan Li
Advisor/Mentor: S. Berry
Major: Biochemistry & Molecular Biology / Cell Biology & Molecular Biology
Hometown: Beijing, P.R.China
My project focuses on Bioinorganic chemistry and electro-chemistry. Protein Azurin belongs to the Blue copper binding protein family and has a redox potential of 305 mV. Azurin binds to a Cu +2 ion to transfer electron in organism.
The hypothesis of the research is to prove that the redox potential of the protein is partly determined by the amino acid charge distribution surrounding the copper binding site. In the case of Azurin, the Cu +2 ion is reduced to Cu +1 when accepting an electron. If the amino acid residues surrounding the copper ion are negatively charged, the positive charge of Cu +2 is stabilized, thus increasing its redox potential.
Plasmid of wild type e.Coli has been genetically remodeled with an insertion of Azurin gene to express Azurin protein in the cells. Azurin gene on plasmid is further remodeled with several changes in amino acids. The positively charged amino acids surrounding the copper binding site (Leu88, Met44, Leu33 and Met 13) are substituted into neutral amino acids Phenylalanines. Binding of the copper ion to the mutant is stable under the inspection of EPR (Electron paramagnetic resonance). Due to the elimination of positive charge environment surrounding the copper binding site, the redox potential of mutant Azurin is increased to 432.5mV by the inspection of cyclic voltammetry.
Why was I interested/ How do I feel about UROP?:
Doing research is a chance that applies your own "class learned" knowledge into the real world. Earning research experience is important and valuable for a science student. It makes you understand more about the knowledge in the book, and also provides you a good background for your future, such as graduate student application.
UMD is a leader in undergraduate research among universities in the US. Giving undergraduate students research opportunity and funding is a good way to allow students to experience the real science research, also it benefits the professors by reducing their working pressure.
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