@article {Hathout1395, author = {Y Hathout and D Fabris and M S Han and R C Sowder, 2nd and L E Henderson and C Fenselau}, title = {Characterization of intermediates in the oxidation of zinc fingers in human immunodeficiency virus type 1 nucleocapsid protein P7.}, volume = {24}, number = {12}, pages = {1395--1400}, year = {1996}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, abstract = {Oxidants targeted toward inactivation of the nucleocapsid zinc finger protein are under development as antiviral agents, especially for use against human immunodeficiency virus. In the present study, electrospray ionization-mass spectrometry is used to follow in situ the progress of the reactions of 2,2{\textquoteright}-dithiodipyridine and disulfiram with recombinant nucleocapsid protein p7 (Ncp7) from human immunodeficiency virus-1 at pH 7.4. Both reagents react with the two zinc fingers in the protein, resulting in the ejection of two zinc ions and the formation of oxidized apo-Ncp7 with three intramolecular disulfide bonds. The ejection of zinc by 2,2{\textquoteright}-dithiodipyridine occurs in two steps. Alkylation of unreacted cysteine residues with N-ethylmaleimide after a 2-min reaction with 2,2{\textquoteright}-dithiodipyridine reveals that the carboxyl-terminal zinc finger is disrupted first. Cys-49, Cys-36, and, to a lesser extent, Cys-39 are all shown to be target residues for initial electrophilic attack. In the reaction of disulfiram with Ncp7, ejection of the two zinc ions also occurs in two steps; however, the fully oxidized apo-Ncp7 is formed more rapidly. Thus, after a 40-min reaction, 45\% of native Ncp7 is oxidized by 2,2{\textquoteright}-dithiodipyridine, whereas 75\% is oxidized by disulfiram.}, issn = {0090-9556}, URL = {https://dmd.aspetjournals.org/content/24/12/1395}, eprint = {https://dmd.aspetjournals.org/content/24/12/1395.full.pdf}, journal = {Drug Metabolism and Disposition} }