Két Chemistry a European Journal cikk 2015 (letölthetők)
abstract: Transition between conformational states in pro-
teins is being recognized as a possible key factor of function.
In support of this, hidden dynamic NMR structures were de-
tected in several cases up to populations of a few percent.
Here, we show by two- and three-state analysis of thermal
unfolding, that the population of hidden states may weight
20–40 % at 298 K in a disulfide-rich protein. In addition, sen-
sitive 15N-CEST NMR experiments identified a low populated
(0.15 %) state that was in slow exchange with the folded PAF
protein. Remarkably, other techniques failed to identify the
rest of the NMR “dark matter”. Comparison of the tempera-
ture dependence of chemical shifts from experiments and
molecular dynamics calculations suggests that hidden con-
formers of PAF differ in the loop and terminal regions and
are most similar in the evolutionary conserved core. Our ob-
servations point to the existence of a complex conforma-
tional landscape with multiple conformational states in dy-
namic equilibrium, with diverse exchange rates presumably
responsible for the completely hidden nature of a considera-
ble fraction.
abstract: A broadband proton–proton-decoupled CPMG-
HSQMBC method for the precise and direct measurement of
long-range heteronuclear coupling constants is presented.
The Zangger–Sterk-based homodecoupling scheme reported
herein efficiently removes unwanted proton–proton split-
tings from the heteronuclear multiplets, so that the desired
heteronuclear couplings can be determined simply by meas-
uring frequency differences between singlet maxima in the
resulting spectra. The proposed pseudo-1D/2D pulse se-
quences were tested on nucleotides, a metal complex incor-
porating P heterocycles, and diglycosyl (di)selenides, as well
as on other carbohydrate derivatives, for the extraction of
n1J( H, 31P), nJ(1H,77Se), and nJ(1H,13C) values, respectively.
Események
2014-04-23 10:31:29
NMR, A VILÁGMINDENSÉG, MEG MINDEN...
Az előadás során ifj. Szántay Csaba (Richter Gedeon Nyrt) az NMR spektroszkópia elméletének világából vett példákon és néhány szerkezetkutatási érdekességen keresztül tudományfilozófiai gondolatokat fog megosztani az érdeklődőkkel. Az előadást követően büfé várja az érdeklődőket.
május 14. szerda, DE-ETK F008-009 előadó
Bővebben »
2014-06-17 11:00:00
THEORY OF SINGLE-MOLECULE FLUORESCENCE AND FORCE SPECTROSCOPY :
Szabó Attila (NIH) MTA külső tag székfoglalója, MTA, Budapest, június 17. kedd, 11:00
Szabó Attila valószínűleg az egyik legtöbbet idézett magyar tudós. Fiziko-kémikus, de munkássága szerteágazó. Írt kvantummechanika könyvet, az NMR relaxációhoz kapcsolható Lipari-Szabo módszert ezrek idézték, kritizálta a Levinthal paradoxont és újabban az egy-molekulás jelenségekkel foglalkozik.