title: The solution NMR structure of a blue-green algae hepatotoxin, microcystin-RR--a comparison with the structure of microcystin-LR.
abstract: The microcystin-RR structures are compared with the structures of microcystin-LR in solution as well as in the crystal structure of the complex with protein phosphatase. The gross structures of the two peptides are similar, but with a more accentuated and compact saddle structure for microcystin-RR. The structural differences affect the hydrogen-bond pattern in the peptides and the location of the side chain of N-methyldehydroalanine, both of which are important for the ability of the peptide to form a tight complex with protein phosphatase. These structural differences may contribute to the observed differences in toxicity of microcystin-RR and microcystin-LR.
authors.affiliation: Department of Organic Chemistry, Umeå University, Sweden.
authors.forename: G B
authors.initials: GB
authors.lastname: Trogen
authors.forename: U
authors.initials: U
authors.lastname: Edlund
authors.forename: G
authors.initials: G
authors.lastname: Larsson
authors.forename: I
authors.initials: I
authors.lastname: Sethson
mesh_terms: D000458:Cyanobacteria / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008387:Marine Toxins; D052998:Microcystins; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000737:chemistry*; D010749:Phosphoprotein Phosphatases / Q000737:chemistry; D013696:Temperature
chemical_list: D008387:Marine Toxins; D052998:Microcystins; D010456:Peptides, Cyclic; C063855:microcystin RR; D010749:Phosphoprotein Phosphatases; C057862:cyanoginosin LR