Title

THE EFFECT OF PROTEIN STABILITY ON AN ELECTRON TRANSFER PROTEIN

Presenter Information

Matthew Goldes

Presentation Type

Poster

Abstract

Proteins are macromolecules essential to all living organisms. They consist of amino acids linked together by peptide bonds. The sequence of amino acids is important because it determines structure, which determines function. The function of a protein can be altered by mutation of the amino acid sequence. Mutations can also change the stability of a protein. The protein utilized in this project, known as cytochrome c (cytc), plays a key role in electron transport and is also involved in apoptosis (programmed cell death). The active site of cytc contains a heme group and the surrounding protein matrix is referred to as the heme crevice. My project involves the mutagenesis of human to spider monkey cytc and experiments that measure changes in local and global stabilities of both proteins and three intermediates created in the mutagenesis process. Using guanidine hydrochloride denaturation followed by circular dichroism spectroscopy, we have shown that the global stabilities of human and spider monkey cytc are similar, yet previous studies indicate that human cytc has greater local stability about the heme crevice than spider monkey cytc. We predict that the changes in local stability are due to certain mutations induced into the protein sequence. Continued experiments that measure this local stability will help pin-point the residues causing changes in local stability. With this information, we can determine the effect that the change in stability has on the dynamics of each protein variant, as it relates to the function of cytc in electron transport and apoptosis.

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Apr 15th, 11:00 AM Apr 15th, 12:00 PM

THE EFFECT OF PROTEIN STABILITY ON AN ELECTRON TRANSFER PROTEIN

UC South Ballroom

Proteins are macromolecules essential to all living organisms. They consist of amino acids linked together by peptide bonds. The sequence of amino acids is important because it determines structure, which determines function. The function of a protein can be altered by mutation of the amino acid sequence. Mutations can also change the stability of a protein. The protein utilized in this project, known as cytochrome c (cytc), plays a key role in electron transport and is also involved in apoptosis (programmed cell death). The active site of cytc contains a heme group and the surrounding protein matrix is referred to as the heme crevice. My project involves the mutagenesis of human to spider monkey cytc and experiments that measure changes in local and global stabilities of both proteins and three intermediates created in the mutagenesis process. Using guanidine hydrochloride denaturation followed by circular dichroism spectroscopy, we have shown that the global stabilities of human and spider monkey cytc are similar, yet previous studies indicate that human cytc has greater local stability about the heme crevice than spider monkey cytc. We predict that the changes in local stability are due to certain mutations induced into the protein sequence. Continued experiments that measure this local stability will help pin-point the residues causing changes in local stability. With this information, we can determine the effect that the change in stability has on the dynamics of each protein variant, as it relates to the function of cytc in electron transport and apoptosis.