Structural aspects of inotropic bipyridine binding. Crystal structure determination to 1.9 A of the human serum transthyretin-milrinone complex.Wojtczak, A., Luft, J.R., Cody, V.
(1993) J.Biol.Chem. 268: 6202-6206
- PubMed: 8454595
- PubMed Abstract:
- An X-Ray Study of the Subunit Structure of Prealbumin
Blake, C.C.F.,Swan, I.D.A.,Rerat, C.,Berthou, J.,Laurent, A.,Rerat, B.
(1971) J.Mol.Biol. 61: 217
- Structure of Human Plasma Prealbumin at 2.5 Angstroms Resolution, a Preliminary Report on the Polypeptide Chain Conformation, Quaternary Structure and Thyroxine Binding
Blake, C.C.F.,Geisow, M.J.,Swan, I.D.A.,Rerat, C.,Rerat, B.
(1974) J.Mol.Biol. 88: 1
- Crystal Structure Determination at 2.3 Angstroms Resolution of Human Transthyretin-3', 5'-Dibromo-2',4,4',6-Tetrahydroxyaurone Complex
Ciszak, E.,Cody, V.,Luft, J.R.
(1992) Proc.Natl.Acad.Sci.USA 89: 6644
- Dayhoff, M.O.
(1976) Atlas of Protein Sequence and Structure,Supplement 2 5: 265
- Mechanism of Molecular Recognition. Structural Aspects of 3,3'-Diiodo-L-Thyronine Binding to Human Serum Transthyretin
Wojtczak, A.,Luft, J.,Cody, V.
(1992) J.Biol.Chem. 267: 353
- Protein-DNA and Protein-Hormone Interactions in Prealbumin, a Model of the Thyroid Hormone Nuclear Receptor (Query)
Blake, C.C.F.,Oatley, S.J.
(1977) Nature 268: 115
- Feldmann, R.J.
(1976) Atlas of Macromolecular Structure on Microfiche --: 549
The crystal structure of human transthyretin (TTR) complexed with milrinone (2-methyl-5-cyano-3,4'-bipyridin-6(1H)-one), a positive inotropic cardiac agent, has been refined to R = 17.4% for 8-1.9-A resolution data. This report provides the first det ...
The crystal structure of human transthyretin (TTR) complexed with milrinone (2-methyl-5-cyano-3,4'-bipyridin-6(1H)-one), a positive inotropic cardiac agent, has been refined to R = 17.4% for 8-1.9-A resolution data. This report provides the first detailed description of protein interactions for an inotropic bipyridine agent which is an effective thyroid hormone binding competitor to transthyretin. Milrinone is bound along the 2-fold axis in the binding site with its substituted pyridone ring located deep within the channel of the two identical binding domains of the TTR tetramer. In this orientation the 5-cyano group occupies the same site as the 3'-iodine in the TTR complex with 3,3'-diiodothyronine (Wojtczak, A., Luft, J., and Cody, V. (1992) J. Biol. Chem. 267, 353-357), which is 3.5 A deeper in the channel than thyroxine (Blake, C. C. F., and Oately, S. J., (1977) Nature 268, 115-120). These structural results confirm computer modeling studies of milrinone structural homology with thyroxine and its TTR binding interactions and explain the effectiveness of milrinone competition for thyroxine binding to TTR. To understand the weaker binding affinity of the parent inotropic drug, amrinone (5-amino-3,4'-bipyridin-6(1H)-one), modeling studies of its TTR binding were carried out which indicate that the 5-amino group cannot participate in strong interactions with TTR and the lack of the 2-methyl further weakens amrinone binding.
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