title: Two-dimensional alanine scanning mutational analysis of the interaction between the vitamin D receptor and its ligands: studies of A-ring modified 19-norvitamin D analogs.
abstract: To clarify the structure-function relationship (SFR) of vitamin D analogs in terms of their interaction with the vitamin D receptor (VDR), we have proposed a new approach, two-dimensional alanine scanning mutational analysis (2D-ASMA). In this paper, attention was focused on the interactions around the A-ring of vitamin D. For this purpose, we synthesized four new 2-substituted 19-norvitamin D derivatives (3-6). The VDR affinity (3-6: 1, 5, 2 and 1/140, respectively) and transcriptional activity (3-6: 10, 30, 2 and 0.3, respectively) of the four compounds were evaluated relative to 1,25-(OH)(2)D(3) (5) (normalized to 1). Then, the transcriptional activities of wild-type and 18 mutant VDRs induced by the four compounds (3-6) were investigated. The results of this 18 x 4 2D-ASMA were presented as a patch table, and the effects of the mutations were analyzed in comparison with the natural hormone (1) and 2-methylene-19-nor-20-epi-1,25-(OH)(2)D(3) (2MD, 2). Of the four A-ring analogs, the 2alpha-hydroxyethoxy derivative (3) showed striking differences in the pattern on the patch table. From the results, we suggest a docking mode of this compound (3) in which the A-ring adopts the alpha conformation.
authors.affiliation: School of Biomedical Science, Tokyo Medical and Dental University, Tokyo 101-0062, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Shimizu
authors.forename: Keiko
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Mika
authors.initials: M
authors.lastname: Mihori
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Iwasaki
authors.forename: Daisuke
authors.initials: D
authors.lastname: Morizono
authors.forename: Sachiko
authors.initials: S
authors.lastname: Yamada
mesh_terms: D000409:Alanine / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D018167:Receptors, Calcitriol / Q000378:metabolism*; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000378:metabolism
chemical_list: D017931:DNA Primers; D008024:Ligands; D018167:Receptors, Calcitriol; D014807:Vitamin D; D000409:Alanine