停流CD光谱法研究硫酸镍与Rochelle Salt的络合反应

停流CD是一种著名的探测蛋白质展开和重折叠过程的方法，以在毫秒尺度上获得二级结构信息。停流CD也可以用于蛋白质动力学领域之外，以观察复杂的形成反应。过渡金属配合物通常在光谱的可见到近红外区域表现出吸收带，CD测量可以用来探测该区域发生的结构变化。结论本应用说明表明，J-1500 CD光谱仪和SFS-562T停流附件可用于监测复杂形成反应及其完成时间。Application NoteCDSSpectroscopy A measurement of the complex formingreaction of nickel sulfate and Rochelle salt2/3Application Note A measurement of the complex forming reaction of nickel sulfate and Rochelle salt probed by stopped-flow CD spectroscopy Stopped-f l o w CD is a well-k nown method t o pr obe the u n f ol d ing a n d refo l di n g proc e s s e s of pr o tein s in ord er to o b t a i n sec o n dary stru c tu r e i n f o rm a t io n o n a mi lli sec o n d t i m e scale. Stopped-flo w CD can also be used outs i de t he real m o f pro t e i n d ynami c s ， t o o b serv e c ompl ex-f o r ming re acti o n s.Tr a n sit io n met a l c o m pl e x es typ i c a ll y e x h i bit a b s o rp ti on b an ds in th e v i sible t o n ear-in frared region of th e spec t ru m an d CD m e a s urem e n ts c an b e used t o pr o b e s tr uc t u r a l c han ges oc c u rr i n g in th i s r eg i o n Th i s ap pli c a tio n n ot e d e mon s tra t e s th e mea su r em e n t of the c omplex-forming reac ti on of n ickel s u lfate a n d Rochelle sa lt u sing a Hi g h Sp ee d St o pp ed-F l ow s y s t e m co nsi s t in g of a J -1500 CD spe c t r omet e r an d a SFS-562T s topped -f lo w a ccessory . Keywords J-1500， c ir c u l a r di c h r o i sm， s t opped -f low， SFS-562T ， t r a n si ti o n me t a l c omple x e s ， k in eti c s， in f r a r e d ， vi sible， c h emical JASCO INC. 28600 Mary's Court ， Ea s t on， MD 21601 U S A Measurement wavelength 1nm Path length 2mm Spectral bandwidth 5 nm and 10 nm Data pitch 1msec Accumulations 75 and 50 times Response time 2 msec Syringe 1 0.24 M nickel sulfate Syringe 2 0.36 M Rochelle salt Mixing ratio 100 uL：100 uL Total flow rate 5 mL/sec Results Figu r e 1 illu s trates the C D s p ectra of 1：1 solu ti o n sampl e of n ickel s u lfat e an d Roche l l e salt. The CD s p ec tr um exhibits a s i ng l e， broad pea k f rom th e u ltra v io l et (UV)-vis ibl e t o n ea r i n fr a red (NIR) r egion. Figure 1. CD spectra of 0.24 M nickel sulfate and 0.36 M Rochelle salt i n a 10 mm path length cell . The s topp e d-flow C D s p e ctra of n ickel su lf a t e an d Ro c h e ll e sa lt a re s h o w n in Fi gure 2-4. T he d ata ill u st ra t e d in F igur e 2w e r e ob t a in e d a t 720 n m a n d F igur e 3 were o btain ed a t 1000 n m. Fi gure 4 s hows b o th th e spe c tr a o b t a ine d at 720 an d 1000 nm f or compa ri son. After 100 m se c th e d at a fo r both w avelengt h s be g in to level off， in dicating th at the com p lex-for ming r ea ct io n is c o mp l et e. T h is also me an s th a t th e data me asur e d a t bo th 720 a n d 1000 n m o b s e r ve the s am e re a c ti o n pr o c e s s . 28600 Mary's Cour t ， E asto n ， MD 21601US A Figure 2. The complex formation of nickel sulfate and Rochelle salt as measured by stopped-f low CD at 720 nm Figure 3. The complex formation of nickel sulfate and Rochelle salt as measured by stopped-flow CD at 1000 nm Figure 4. The complex formation of nickel sulfate and Rochelle salt as measured by stopped-flow CD at 720 nm (blue) and 1000 nm (green) Conclusion This application not e de m on s tr ates t h a t th e J-1500 CD spect r om eter a n d SFS-562T s t o p ped -f low a c c e sso r y can be u s e d to mon it or c o mple x -f or min g r eaction s a n d their com p let i on t im e. References 1. Miy ak e ， H .， S ug imot o， H.， T a mi a ki ， H.， a nd H. Tsu k ub e ，(2005) C h e m. C o mmun .， 429104293. 2. Miy ake，H.， K amon ， H .， I k u ko ， M .， S u gimot o ， H.， an d H. Tsu k u b e， (2008)， JA C S， 130， 792-793 28600 Mary's Cour t ， E asto n ， MD 21601US A