Title

Genotypic Expression Behind the Tall and Dwarf Peaks in Peptide Fragmentation

Lead Author Major

Chemistry

Lead Author Status

Sophomore

Second Author Major

Biochemistry

Second Author Status

Senior

Format

Poster Presentation

Faculty Mentor Name

Jianhua Ren

Faculty Mentor Department

Chemistry

Graduate Student Mentor Name

Yadwinder Singh Mann

Graduate Student Mentor Department

Chemistry

Abstract/Artist Statement

Introduction:

Why is it that in peptide fragmentation there are intense peaks and others that are small? The present experiment has allowed us to investigate the reason behind this question. Although the peptides fragment at various positions along the backbone, ions produced from the fragmentation of the amide backbone are highly abundant compared to other ions. The C terminal ions and the N terminal ions are referred to as b and y ions respectively. Peptides mostly produce high intensity of b2 ions while the peptide analogues, peptoids, have higher intensity of Y ions. In peptoids, the basicity of the Y ions could be the possible reason behind this phenomenon. The position of the side chain in the peptoid leads to the higher basicity of C terminal ions as the amine is secondary.

In order to test out the hypothesis that basicity increases the abundance of ions or not in peptides, solid phase peptide synthesis (SPPS) was used to synthesize proline containing peptides as the genetic makeup is similar to peptoids. The C-terminal ions in proline containing peptides are similar to peptoids, as they have a higher basicity compared to other peptides.

Method:

The peptide PPPP (P4), GGGG (G4), and GGPG were synthesized using solid phase peptide synthesis (SPPS) procedure. Liquid nitrogen was used to solidify the solution, which was then placed in a lyophilizer to purify the peptides. The Varian 320 mass spectrometer instrument was used to confirm the identity and analyze the fragmentation pattern.

Result:

This research has shown that there is a higher abundance of y-ions in P4 when comparing it to G4. Which is explained by the similarity of proline peptides to peptoids and increased basicity. Thus, concluding that the basicity of the peptide synthesized will change the fragmentation pattern in relation to the peak intensity of b-ions and y-ions.

Location

Virtual

Start Date

25-4-2020 1:00 PM

End Date

25-4-2020 3:00 PM

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Apr 25th, 1:00 PM Apr 25th, 3:00 PM

Genotypic Expression Behind the Tall and Dwarf Peaks in Peptide Fragmentation

Virtual

Introduction:

Why is it that in peptide fragmentation there are intense peaks and others that are small? The present experiment has allowed us to investigate the reason behind this question. Although the peptides fragment at various positions along the backbone, ions produced from the fragmentation of the amide backbone are highly abundant compared to other ions. The C terminal ions and the N terminal ions are referred to as b and y ions respectively. Peptides mostly produce high intensity of b2 ions while the peptide analogues, peptoids, have higher intensity of Y ions. In peptoids, the basicity of the Y ions could be the possible reason behind this phenomenon. The position of the side chain in the peptoid leads to the higher basicity of C terminal ions as the amine is secondary.

In order to test out the hypothesis that basicity increases the abundance of ions or not in peptides, solid phase peptide synthesis (SPPS) was used to synthesize proline containing peptides as the genetic makeup is similar to peptoids. The C-terminal ions in proline containing peptides are similar to peptoids, as they have a higher basicity compared to other peptides.

Method:

The peptide PPPP (P4), GGGG (G4), and GGPG were synthesized using solid phase peptide synthesis (SPPS) procedure. Liquid nitrogen was used to solidify the solution, which was then placed in a lyophilizer to purify the peptides. The Varian 320 mass spectrometer instrument was used to confirm the identity and analyze the fragmentation pattern.

Result:

This research has shown that there is a higher abundance of y-ions in P4 when comparing it to G4. Which is explained by the similarity of proline peptides to peptoids and increased basicity. Thus, concluding that the basicity of the peptide synthesized will change the fragmentation pattern in relation to the peak intensity of b-ions and y-ions.