title: Spectroscopic investigations of HIV-1 trans-activator and related peptides in aqueous solutions.
abstract: The 86 amino acid trans-activator (Tat) protein of human immunodeficiency virus type 1 (HIV-1) is an RNA-binding transcriptional regulator. HIV-1 Tat proteins (wild type and Thr40Lys mutant) and the HIV-1 Tat peptide fragments Tat(32-48) and Tat(32-72) were chemically synthesized. One- and two-dimensional nuclear magnetic resonance spectroscopy experiments were performed to elucidate the structural features of these proteins. In fluorescence quenching studies of the full-length Tat protein (Thr40Lys), Trp11 was found to be only partially protected against solvent accessibility. Circular dichroism melting studies monitored a slight cooperative change in the conformation of the Tat with increasing temperature. Backbone NH protons of amino acids located in the main core element of the protein are partially protected against exchange.
authors.affiliation: Lehrstuhl für Biopolymere, Universität Bayreuth, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Klostermeier
authors.forename: P
authors.initials: P
authors.lastname: Bayer
authors.forename: M
authors.initials: M
authors.lastname: Kraft
authors.forename: R W
authors.initials: RW
authors.lastname: Frank
authors.forename: P
authors.initials: P
authors.lastname: Rösch
mesh_terms: D000595:Amino Acid Sequence; D002942:Circular Dichroism; D015694:Gene Products, rev; D015696:Gene Products, tat / Q000737:chemistry; D015497:HIV-1 / Q000737:chemistry* / Q000235:genetics; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D054321:rev Gene Products, Human Immunodeficiency Virus; D054322:tat Gene Products, Human Immunodeficiency Virus
chemical_list: D015694:Gene Products, rev; D015696:Gene Products, tat; D010455:Peptides; D054321:rev Gene Products, Human Immunodeficiency Virus; D054322:tat Gene Products, Human Immunodeficiency Virus