Nucleocapsid protein of HIV-1 and its Zn2+ complex formation analysis with electrospray mass spectrometry.
The Zn2+ binding properties of the synthetic nucleocapsid protein (Ncp7) of HIV-1, containing two zinc-binding domains, have been studied using electrospray mass spectrometry (ES-MS). ES-MS measurements revealed strong binding of Zn2+ by Ncp7. Its shorter fragments, Ncp7-(1-35)- and (29-55)-peptides, each containing only one zinc-binding domain, bind one equivalent of Zn2+ ions tightly. ES-MS studies allows these fragments to be distinguished in terms of their binding affinity: they showed stronger binding of Zn2+ by Ncp7-(1-35)-peptide. Surprisingly, in addition to the expected two zinc-binding domains, a third metal binding site was detected in Ncp7. However, this site appears to bind different metal ions without selectivity and most probably reflects salt formation at the C-terminal acidic residues.
Surovoy
A
A
Shemyakin Institute of Bioorganic Chemistry, Moscow, Russia.
Waidelich
D
D
Jung
G
G
D000595:Amino Acid Sequence; D001665:Binding Sites; D036022:Capsid Proteins; D015683:Gene Products, gag / Q000737:chemistry* / Q000378:metabolism*; D015497:HIV-1 / Q000378:metabolism*; D013058:Mass Spectrometry / Q000379:methods; D008969:Molecular Sequence Data; D011487:Protein Conformation; D014764:Viral Proteins; D015032:Zinc / Q000378:metabolism*; D054301:gag Gene Products, Human Immunodeficiency Virus
D036022:Capsid Proteins; D015683:Gene Products, gag; C071884:NCP7 protein, Human immunodeficiency virus 1; D014764:Viral Proteins; D054301:gag Gene Products, Human Immunodeficiency Virus; D015032:Zinc