Extended binding sites of cyclophilin as revealed by the interaction with HIV-1 Gag polyprotein derived oligopeptides
| Autor: | Steffen Wöllner, Mario Drewello, Gunter Fischer, Angelika Schierhorn, Gerd Scherer, Ulf Reimer, Mike Schutkowski, Mario Jakob |
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| Jazyk: | angličtina |
| Předmět: |
Protein Conformation
Stereochemistry Molecular Sequence Data Biophysics Gene Products gag Biochemistry Protein structure Structural Biology Genetics Humans Amino Acid Sequence Protein Precursors Binding site Selective binding Molecular Biology Peptide sequence Cyclophilin HIV-1 Gag polyprotein Amino Acid Isomerases Polyproline helix Peptidylprolyl isomerase Binding Sites biology Chemistry Circular Dichroism CD spectroscopy Active site Cell Biology Peptidylprolyl Isomerase Recombinant Proteins Kinetics FKBP Peptide HIV-1 biology.protein Carrier Proteins Oligopeptides Protein Binding |
| Zdroj: | FEBS Letters. (3):289-294 |
| ISSN: | 0014-5793 |
| DOI: | 10.1016/0014-5793(96)00972-6 |
| Popis: | Oligopeptides derived from the gag polyprotein (Pr55gag) of human immunodeficiency virus type 1 (HIV-1) segment were used to evaluate the extension of the putative binding region for the complex of Pr55gag and the human cytosolic peptidyl prolyl cisltrans isomerase (PPIase) 18 kDa cyclophilin (Cyp18). Five N-terminally acetylated, C-terminally amidated oligopeptides containing one (HIV-1 Gag 218–224; 1), two (HIV-1 Gag 218–226 and HIV-1 Gag 217−224; 2 and 3, respectively), three (HIV-1 Gag 217–226; 4) or four (HIV-1 Gag213−237; 5) proline residues were synthesized. Using competition experiments with a standard substrate the binding affinities to Cyp18 of the synthesized peptides were determined. The IC50 value of 184 μ.M for the 25-mer peptide 5 was fivefold or more lower than those of the peptides 1–4 lacking one or more prolines. Failure of competition in assays containing enzymes of other PPIase families by millimolar concentrations of 5 revealed a Cyp18 specific interaction involving the active site of the enzyme. In its far UV circular dichroism, aqueous solutions of 5 display properties of random coil conformation, but spectra were also consistent with a small contribution of proline specific secondary structures. However, a proline-rich peptide typical of forming left-handed polyproline II helices did not compete for the active site of Cyp18. The results demonstrate that the putative binding region of HIV-1 gag polyprotein has a certain degree of binding affinity to the PPIase site of Cyp18, and may add a previously unrecognized topological component to the known subsite specificity of cyclophilins. |
| Databáze: | OpenAIRE |
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