Energy-Resolved Threshold Collision-Induced Dissociation of Zinc(II) Ternary Complexes of Alternative Metal Binding Peptides with Nitrilotriacetic Acid

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

Date of Award

1-10-2024

Abstract

Energy-resolved threshold collision-induced dissociation (TCID) of negatively- charged [amb+Zn(II)+NTA]− ternary complexes were studied for how they competitively dissociated into the products [amb+Zn(II)]− + NTA or [NTA+Zn(II)]− + amb, where NTA is nitrilotriacetic acid, to determine an alternative metal binding (amb) peptide that exhibits similar characteristics to the commercially used His-tag in the purification of recombinant proteins. The ternary complexes contained one of the amb5 peptides with the primary structures acetyl-Aa1-Aa2-Gly3-Pro4-Aa5-Gly6- Cys7, where the amino acids Aa1 and Aa2 are the potential metal binding sites of His, Asp or Cys and Aa5 is either Tyr or Gly. The results described here focus on four heptapeptide sequences named; amb5C (acetyl-His1-Cys2-Gly3-Pro4-Tyr5-Gly6-Cys7), amb5S (acetyl-Asp1-His2-Gly3-Pro4-Gly5-Gly6-Cys7), amb5V (acetyl-Asp1-His2-Gly3- Pro4-Tyr5-Gly6-Cys7) and amb5Y (acetyl-His1-Cys2-Gly3-Pro4-Gly5-Gly6-Cys7). Reaction cross sections (RCS) of the ternary complexes will be determined using the Beer’s law that quantifies the interaction of the ternary complex to form the products as a function of center-of-mass collision energy. The RCSs will also be modelled using the molecular dynamics program CRUNCH to extract the thermochemistry of the reactions. Collision cross sections (CCS) of the reactant and product ions are determined to help select conformers from PM6 calculations that are used in the CRUNCH modelling.

Advisor

Laurence Angel

Subject Categories

Chemistry | Physical Sciences and Mathematics

Link to Full Text

Share

COinS