使用OneDrop微采样盘测量CD光谱

智能文字提取功能测试中

与核磁共振和x射线晶体学一样，CD光谱学是蛋白质结构分析中不可或缺的测量方法。由于小体积和/或低浓度是CD样品测量的典型要求，JASCO开发了一种新的取样技术来满足这些样品的要求。本应用说明表明，一滴微采样盘是一种易于使用的方法，可为小体积和低浓度的样品获得可靠和快速的结果。Application NoteCDSSpectroscopy Use of a microsampling disc for One-Drop CDspectra measurement2/3Application Note Use of a microsampling disc for One-Drop CD spectra measuremen t A l ong with NMR a n d X-ray crystallography， CD spect r oscopy i s a n indi sp en s a ble m e a su remen t meth od fo r pro t ei n s t ru c ture an alysi s . S in c e s mall v o lu m e s an d/or low conce n tration s a r e a t yp i ca l r equi r e m e n t f or C D sam p le m ea s uremen ts， JA SCO ha s d ev e l o p ed a n o vel s am plin g t ec h ni q ue t o mee t th ese s a mpl e re q uire m en t s . The t ec h ni q ue u ses a On e-D ro p mi c r o s ampling d i s c (MSD)，w h i c h i s shown in F i g u re 1. CD m easuremen t s u s i ng the On e-Dr o p MSD h a v e th e fo l l ow in g a d v a n tages ： 1. Sm a ll v o lu me r eq u iremen t s ： 10 u L (1 mm p a th l e n gth )， 2u L (0.2 mm p a th l e ngt h ) 2. Ea s y hand l ing o f MSD： h y d r o ph obic treatmen t o f l e n s k eep s s a m p l es ce n tered i n d i sc 3. V a r ia ble pa t h l e n gt h： sp a cer s a v ail a ble fo r 1 o r 0.2 mm path l eng t h 4. MSD win do ws pr o vi d e ar ti fact-fre e meas u r e me n t s 5. JASCO C D s p ectrometers use a parall e l light be a m so there is no n eed fo r al i gnme n t 6. Hi g h l y r epro d u cibl e basel i ne T h i s a ppl i c at io n n o te wi ll demon st ra t e th e e a s e an d e ff i c ien cy of th e O n e -D r op micro s a mpli n g d i s c b y m ea s u ring the CD spectra of four protei n s . Keywords One-drop meas ur eme n t， microsampl in g d i sc， circ u la r d i c h r o i sm， seco n dar y s tr uc tu re ，J -1500 JASCO J-1500 CD spectrometer View product information at ww w.j a s co in c.c om Figure 1. Microsampling disc components (demountable cell ， 2 windows and a spacer) Experimental Measurement conditions J-1500 CD spectrometer，MSD， conventional cell Spectral bandwidth 1nm Accumulation 4 times (MSD)， 1 time (conventional cell) Data acquisition interval 0.1nm Measurement time 2.8 min (MSD)， 42 sec (conventional cell) Scan speed 100 nm/min Response time 2 sec Path length 1mm Sample concentration 0.1 mg/mL To use th e m icro s a mp lin g d i sc shown in F i g ur e 1， the s a m p le is dro p ped on t o th e cen tra l p art of the MSD. The disc i s ther a s sembled a n d c la m ped . T h e MS D i s then p laced in a v e r tica l p o s i ti o n in the sa mpl e holder . MSD sample chamber Figure 2. Diagram of procedure for using the microsampling disc Results T he C D sp ectr a dep i cte d in Fi gure 3 c o m p a re t he res u lt s o bt a ine d u s i n g t he M S D an d a co n v en t io n al cel l. T h e microsam p l i ng disc (green line) provided near i d en ti cal spectra compared to t h e cyli n drical cell (b l ue li n e) used . Th e d at a also sh ow th at seco n da ry s tr u ctu re b e t w ee n 260 a n d 190 n m c an b e me as u r ed in l e ss th an three min u t es u s i ng the MS D