An Investigation into the Adduct Forming Potential of Drugs of Abuse with Peptides and Proteins

Authors

Richard Allen Gilliland, Florida International UniversityFollow

Document Type

Dissertation

Degree

Doctor of Philosophy (PhD)

Major/Program

Chemistry

First Advisor's Name

Anthony DeCaprio

First Advisor's Committee Title

Committee Chair

Second Advisor's Name

Dietrich Lorke

Second Advisor's Committee Title

Committee Member

Third Advisor's Name

Bruce McCord

Third Advisor's Committee Title

Committee Member

Fourth Advisor's Name

Yuk-Ching Tse-Dinh

Fourth Advisor's Committee Title

Committee Member

Fifth Advisor's Name

Yi Xiao

Fifth Advisor's Committee Title

Committee Member

Keywords

Metabolites, Adduct, Mass Spectrometry

Date of Defense

8-29-2018

Abstract

Hemoglobin and serum albumin, two prevalent proteins in human blood, contain unbound cysteine thiol moieties, creating a nucleophilic site with the potential for covalent modification by reactive chemical species. These covalent modifications, called “adducts”, are stable entities that accumulate during acute and chronic exposure and remain covalently bound for the life-span of the protein. Despite their current use as exposure markers for a variety of compounds, the use of adducts in assessing exposure to drugs of abuse has not yet been explored. The goal of this work was to examine the in vitro adduct forming capability of selected drugs of abuse with hemoglobin to provide additional proof of principle for the development of a real-world detection and monitoring analysis method. This goal was accomplished by first analyzing the binding capabilities of the drugs of interest with glutathione, a smaller tripeptide. Use of protein adducts as biomarkers of drug exposure may allow for an increased window of detection, from several days to several months, as compared to current blood analysis methods. In total, there were 16 drugs analyzed in the research, and they covered a wide range of abused drugs, including cocaine, methamphetamine, and Δ 9 -THC.

Results from the glutathione trials showed that 10 of the 16 the drugs of interest were able to form covalent adducts with the free thiol moiety, with four drugs forming more than one novel adduct. The MS results for hemoglobin showed 11 adducts formed for five of the drugs under investigation. Additional MS/MS confirmatory data was obtained for two of those 11 adducts. I successfully identifyied adducts formed between drugs of abuse and glutathione and hemoglobin, which have the potential to be used as long-term biomarkers of exposure.

Identifier

FIDC007036

Recommended Citation

Gilliland, Richard Allen, "An Investigation into the Adduct Forming Potential of Drugs of Abuse with Peptides and Proteins" (2018). FIU Electronic Theses and Dissertations. 3869.
https://digitalcommons.fiu.edu/etd/3869