title: Enzymatic kinetics regarding reversible metabolism of CS-0777, a sphingosine 1-phosphate receptor modulator, via phosphorylation and dephosphorylation in humans.
abstract: 1. CS-0777, a candidate compound for autoimmune diseases, becomes phosphorylated active metabolite, M1, by fructosamine 3-kinase (FN3K), FN3K-related protein (FN3K-RP); and M1 is reverted back to CS-0777 by alkaline phosphatase (ALP) in the body. We performed enzyme kinetic analysis of phosphorylation of CS-0777 by FN3K, FN3K-RP, human erythrocytes and human platelets; and dephosphorylation of M1 by various ALP isozymes and human liver, kidney, lung and small intestine microsomes. 2. The Michaelis constants of human FN3K, FN3K-RP and erythrocytes for CS-0777 phosphorylation were in the range from 498 μM to 1060 μM. FN3K inhibitor, 1-deoxy-1-morpholinofructose, suppressed only about 20% of CS-0777 phosphorylation activity in human erythrocyte lysate. Immunodepletion of FN3K and FN3K-RP decreased M1 formation activity by about 25% and 50%, respectively, in human erythrocyte lysate. 3. The Michaelis constants of four human ALPs and microsomes were in the range from 10.9 μM to 32.1 μM. The ALP inhibitor, levamisole, suppressed over 50% of M1 dephosphorylation activity in liver, kidney and lung microsomes. 4. FN3K-RP is expected to take a prominent role in the phosphorylation of CS-0777 in human erythrocytes; dephosphorylation of M1 was observed in all ALPs and human tissue microsomes examined, with a similar affinity towards M1 among them.
authors.affiliation: a Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co. Ltd , Tokyo , Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Inaba
authors.affiliation: a Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co. Ltd , Tokyo , Japan.
authors.forename: Maki
authors.initials: M
authors.lastname: Yamaguchi-Goto
authors.affiliation: a Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co. Ltd , Tokyo , Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Tanaka-Takanaka
authors.affiliation: b Oncology Laboratories, Daiichi Sankyo Co. Ltd , Tokyo , Japan , and.
authors.forename: Kiyoaki
authors.initials: K
authors.lastname: Yonesu
authors.affiliation: c Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co. Ltd , Tokyo , Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Sakurai
authors.affiliation: c Discovery Science and Technology Department, Daiichi Sankyo RD Novare Co. Ltd , Tokyo , Japan.
authors.forename: Kazuishi
authors.initials: K
authors.lastname: Kubota
authors.affiliation: a Drug Metabolism & Pharmacokinetics Research Laboratories, Daiichi Sankyo Co. Ltd , Tokyo , Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Izumi
mesh_terms: D000469:Alkaline Phosphatase / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D000605:Amino Alcohols / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D005260:Female; D005632:Fructose / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D007421:Intestine, Small / Q000187:drug effects / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000378:metabolism; D007700:Kinetics; D007978:Levamisole / Q000494:pharmacology; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D009025:Morpholines / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011758:Pyrroles / Q000378:metabolism / Q000493:pharmacokinetics / Q000494:pharmacology*; D049349:Receptors, Lysosphingolipid / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000605:Amino Alcohols; C569297:CS 0777; D004791:Enzyme Inhibitors; D009025:Morpholines; D011758:Pyrroles; D049349:Receptors, Lysosphingolipid; D011994:Recombinant Proteins; D007978:Levamisole; D005632:Fructose; C044913:1-deoxy-1-morpholinofructose; C479999:FN3KRP protein, human; D017853:Phosphotransferases (Alcohol Group Acceptor); C414347:fructosamine-3-kinase; D000469:Alkaline Phosphatase
keywords: Alkaline phosphatase; CS-0777; enzymatic kinetics; fructosamine 3-kinase; fructosamine 3-kinase related protein; reversible metabolism