7.3 - NMR Lab, USTC

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生物大分子波谱学原理
吴季辉
Side Chain Assignment
(H)C(CO)NH-TOCSY: Side Chain C chemical shifts
H(CC)(CO)NH-TOCSY: Side chain H chemical shifts
HCCH-COSY: adjacent C-C correlation
HCCH-TOCSY: long range C-C correlation within one residue
生物大分子波谱学原理
吴季辉
CCONH-TOCSY
生物大分子波谱学原理
吴季辉
HCONH-TOCSY
生物大分子波谱学原理
吴季辉
13C-13C相关谱
碳-碳相关谱
HCCH-COSY(1H-13C-13C-1H correlation spectroscopy)
及HCCH-TOCSY(1H-13C-13C-1H total correlation spectroscopy)
用于证认13C标记蛋白质的脂肪链1H及13C,信号传递是从1H开
始,经过单键J偶合到13C,再通过类似同核COSY及TOCSY的
机制传递到其他13C,最后通过单键J偶合回传到1H。所以这类
实验可以看作1H同核COSY及TOCSY在13C上的推广。除了可
以获得13C的信息,也可得到1H的信息,对于大蛋白质而言,
效果比1H同核COSY及TOCSY更好,因为在1H同核COSY及
TOCSY中起作用的是比较小的1H同核J偶合(一般小于10Hz),
而这里虽有三步传递,却均是比较大的J偶合,其中JHC约
140Hz,JCC约35Hz。因此这类实验对于大蛋白质的侧链1H,
13C的证认非常重要。
生物大分子波谱学原理
吴季辉
13C-13C相关谱
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
生物大分子波谱学原理
吴季辉
7.3
13C-13C相关谱
生物大分子波谱学原理
吴季辉
7.3
13C-13C相关谱
生物大分子波谱学原理
吴季辉
7.3
13C-13C相关谱
生物大分子波谱学原理
吴季辉
7.3
13C-13C相关谱
生物大分子波谱学原理
吴季辉
7.3
13C-13C相关谱
Conventional implementation: 1H magnetization is transferred in a
refocused INEPT to 13C in-phase magnetization. After C,C-TOCSY
mixing, the back-transfer is achieved in an analogous manner. The
incrementation of delays required for shared-time evolution in t1 is
also indicated. Note that the C' 180 pulse during the t1 evolution
period is not absolutely required, because 2JH,C' couplings are small.
Doubly sensitivity-enhanced 3D H(C)CH-TOCSY experiment with hetero-nuclear gradient
echo for solvent suppression. The heteronuclear in-phase transfer is implemented with a yxzICOS-CT sequence. Four different combination of gradients  and  and of phase settings 
and  (corresponding to echo/antiecho pathways for both indirect dimensions) have to be
recorded and stored in different memory locations. Modifications required for a semi-constanttime evolution during t1 are indicated. The operator F is the sum of I operators denoting the
proton spins
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