Reaktion #1333763
ord-5f2d541e284841af87c30002733b3558
Reaktionsgleichung
Reagenzien
Reaktionsbedingungen
Aufarbeitung
- 1SonstigeThe insoluble material was removed by centrifugation, and 50 μL of the supernatant
- 2workup.WAIT80% H2O for 1 min
- 3workup.WAITto 100% MeCN over 10 min at 1 mL/min
- 4WaschenUnder these conditions, epothilone D eluted at 11.6 min
Vorschrift
The EpoK assay was performed as follows (See Betlach et al., Biochem (1998) 37:14937, incorporated herein by reference). Briefly, reactions consisted of 50 mM Tris (pH7.5), 21 μM spinach ferredoxin, 0.132 units of spinach ferredoxin: NADP+ oxidoreductase, 0.8 units of glucose-6-phosphate dehydrogenase, 1.4 mM NADP, and 7.1 mM glucose-6-phosphate, 100 μM or 200 μM epothilone D (a generous gift of S. Danishefsky), and 1.7 μM amino terminal his tagged EpoK or 1.6 μM carboxy terminal his tagged EpoK in a 100 μL volume. The reactions were incubated at 30° C. for 67 minutes and stopped by heating at 90° C. for 2 minutes. The insoluble material was removed by centrifugation, and 50 μL of the supernatant were analyzed by LC/MS. HPLC conditions: Metachem 5μ ODS-3 Inertsil (4.6×150 mm); 80% H2O for 1 min, then to 100% MeCN over 10 min at 1 mL/min, with UV (λmax=250 nm), ELSD, and MS detection. Under these conditions, epothilone D eluted at 11.6 min and epothilone B at 9.3 min. the LC/MS spectra were obtained using an atmosphere pressure chemical ionization source with orifice and ring voltages set at 20 V and 250 V, respectively, at a mass resolution of 1 amu. Under these conditions, epothilone E shows an [M+H] at m/z 493, with observed fragments at 405 and 304. Epothilone B shows an [M+H] at m/z 509, with observed fragments at 491 and 320.