Solution structure and stability of a disulfide cross-linked nucleopeptide duplex.
NMR methods are used to study the structure and stability of the duplex formed by the nucleopeptide [Ac-Cys-Gly-Ala-Hse(p3'dGCATGC)-Ala-OH]2[S-S], in which the oligonucleotide is self-complementary and the cysteine residues of the two peptide chains form a disulfide bridge; thermal transitions and NMR-derived structural calculations are consistent with a 3-D structure in which the oligonucleotide forms a standard B-DNA helix without significant distortions; the peptide chains are relatively disordered in solution and lie in the minor groove of the DNA helix; this nucleopeptide duplex exhibits a high melting temperature, indicating that peptide-oligonucleotide conjugates containing cysteines are suitable molecules to establish cross-links between DNA strands and stabilize the duplex.
Instituto de Química Física Rocasolano, C/Serrano 119, 28006 Madrid, Spain.
Irene
I
Gómez-Pinto
Vicente
V
Marchán
Federico
F
Gago
Anna
A
Grandas
Carlos
C
González
D000595:Amino Acid Sequence; D001483:Base Sequence; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D009698:Nucleoproteins / Q000737:chemistry*; D009841:Oligonucleotides / Q000737:chemistry; D011487:Protein Conformation; D012996:Solutions / Q000737:chemistry; D013696:Temperature
D004220:Disulfides; D009698:Nucleoproteins; D009841:Oligonucleotides; D012996:Solutions; D003545:Cysteine