Wiktor Koźmiński's NMR group

Biological and Chemical Research Centre, University of Warsaw

  • Increase font size
  • Default font size
  • Decrease font size
Wiktor Koźmiński's NMR Group

The FEBS Journal Poster Prize

Print

Saurabh Saxena was awarded with The FEBS Journal Poster Prize at ISMAR 2015 conference in Shanghai. Congratulations!

 

New Review in Progress in Nuclear Magnetic Resonance Spectroscopy

Print

Applications of high dimensionality experiments to biomolecular NMR

Michał Nowakowski, Saurabh Saxena, Jan Stanek, Szymon Żerko, Wiktor Koźmiński


Full-size image (11 K)

High dimensionality NMR experiments facilitate resonance assignment and precise determination of spectral parameters such as coupling constants. Sparse non-uniform sampling enables acquisition of experiments of high dimensionality with high resolution in acceptable time. In this review we present and compare some significant applications of NMR experiments of dimensionality higher than three in the field of biomolecular studies in solution.

 

New Article in Journal of Biomolecular NMR

Print

13C-detected NMR experiments for automatic resonance assignment of IDPs and multiple-fixing SMFT processing

Paweł Dziekański, Katarzyna Grudziąż, Patrik Jarvoll, Wiktor Koźmiński, Anna Zawadzka-Kazimierczuk


multfixing

Intrinsically disordered proteins (IDPs) have recently attracted much interest, due to their role in many biological processes, including signaling and regulation mechanisms. High-dimensional 13C direct-detected NMR experiments have proven exceptionally useful in case of IDPs, providing spectra with superior peak dispersion. Here, two such novel experiments recorded with non-uniform sampling are introduced, these are 5D HabCabCO(CA)NCO and 5D HNCO(CA)NCO. Together with the 4D (HACA)CON(CA)NCO, an extension of the previously published 3D experiments (Pantoja-Uceda and Santoro in J Biomol NMR 59:43–50, 2014), they form a set allowing for complete and reliable resonance assignment of difficult IDPs. The processing is performed with sparse multidimensional Fourier transform based on the concept of restricting (fixing) some of spectral dimensions to a priori known resonance frequencies. In our study, a multiple-fixing method was developed, that allows easy access to spectral data. The experiments were tested on a resolution-demanding alpha-synuclein sample. Due to superior peak dispersion in high-dimensional spectrum and availability of the sequential connectivities between four consecutive residues, the overwhelming majority of resonances could be assigned automatically using the TSAR program.

 

New Article in Journal of Biomolecular NMR

Print

“CON-CON” assignment strategy for highly flexible intrinsically disordered proteins

Alessandro Piai, Tomáš Hošek, Leonardo Gonnelli, Anna Zawadzka-Kazimierczuk, Wiktor Koźmiński, Bernhard Brutscher, Wolfgang Bermel, Roberta Pierattelli, Isabella C. Felli


CON CON

Intrinsically disordered proteins (IDPs) are a class of highly flexible proteins whose characterization by NMR spectroscopy is complicated by severe spectral overlaps. The development of experiments designed to facilitate the sequence-specific assignment procedure is thus very important to improve the tools for the characterization of IDPs and thus to be able to focus on IDPs of increasing size and complexity. Here, we present and describe the implementation of a set of novel 1H-detected 5D experiments, (HACA)CON(CACO)NCO(CA)HA, BT-(H)NCO(CAN)CONNH and BT-HN(COCAN)CONNH, optimized for the study of highly flexible IDPs that exploit the best resolved correlations, those involving the carbonyl and nitrogen nuclei of neighboring amino acids, to achieve sequence-specific resonance assignment. Together with the analogous recently proposed pulse schemes based on 13C detection, they form a complete set of experiments for sequence-specific assignment of highly flexible IDPs. Depending on the particular sample conditions (concentration, lifetime, pH, temperature, etc.), these experiments present certain advantages and disadvantages that will be discussed. Needless to say, that the availability of a variety of complementary experiments will be important for accurate determination of resonance frequencies in complex IDPs.

 

Best poster at SMASH

Print

Mateusz Urbańczyk was awarded with best poster award at SMASH NMR!

 

New Article in Biochemical Journal

Print

The solution structure of the MANEC-type domain from Hepatocyte Growth Factor Activator Inhibitor 1 reveals an unexpected PAN/apple domain-type fold.

Zebin Hong, Michał Nowakowski, Chris Spronk, Steen V. Petersen, Peter A Andreasen, Wiktor Koźmiński, Frans A. A. Mulder and Jan K. Jensen


manec

A decade ago, a Motif at N-terminus with Eight-Cysteines or in short MANEC was defined as a new protein domain family. This domain is found exclusively in the N-terminus of >400 multi-domain type-1 transmembrane proteins from animals. Despite the large number of MANEC-containing proteins, only one has been characterized at the protein level: hepatocyte growth factor activator inhibitor-1 (HAI-1). HAI-1 is an essential protein, as knockout mice die in utero due to placental defects. HAI-1 is an inhibitor of matriptase, hepsin and hepatocyte growth factor activator, all serine proteases with important roles in epithelial development, cell growth and homeostasis. Dysregulation of these proteases has been causatively implicated in pathological conditions such as skin diseases and cancer. Detailed functional understanding of HAI-1 and other MANEC-containing proteins is hampered by the lack of structural information on MANEC. Although many MANEC sequences exist, sequence-based database searches fail to predict structural homology. Here we present the NMR solution structure of the MANEC domain from HAI-1, the first three-dimensional structure from the MANEC domain family. Unexpectedly, MANEC is a new subclass of the PAN/apple domain family, with its own unifying features, such as two additional disulfide bonds, two extended loop regions and additional α-helical elements. As shown for other PAN/apple domain-containing proteins, we propose a similar active role of the MANEC domain in intramolecular and intermolecular interactions. The structure provides a tool for the further elucidation of HAI-1 function as well as a reference for the study of other MANEC-containing proteins.

 

New Article in Journal of Biomolecular NMR

Print

C4′/H4′ selective, non-uniformly sampled 4D HC(P)CH experiment for sequential assignments of 13C-labeled RNAs

Saurabh Saxena, Jan Stanek, Mirko Cevec, Janez Plavec, Wiktor Koźmiński


alt

A through bond, C4′/H4′ selective, “out and stay” type 4D HC(P)CH experiment is introduced which provides sequential connectivity via H4′(i)–C4′(i)–C4′(i−1)–H4′(i−1) correlations. The 31P dimension (used in the conventional 3D HCP experiment) is replaced with evolution of better dispersed C4′ dimension. The experiment fully utilizes 13C-labeling of RNA by inclusion of two C4′ evolution periods. An additional evolution of H4′ is included to further enhance peak resolution. Band selective 13C inversion pulses are used to achieve selectivity and prevent signal dephasing due to the of C4′–C3′ and C4′–C5′ homonuclear couplings. For reasonable resolution, non-uniform sampling is employed in all indirect dimensions. To reduce sensitivity losses, multiple quantum coherences are preserved during shared-time evolution and coherence transfer delays. In the experiment the intra-nucleotide peaks are suppressed whereas inter-nucleotide peaks are enhanced to reduce the ambiguities. The performance of the experiment is verified on a fully 13C, 15N-labeled 34-nt hairpin RNA comprising typical structure elements.

 

New Article in Angewandte Chemie International Edition

Print

Accelerating Diffusion-Ordered NMR Spectroscopy by Joint Sparse Sampling of Diffusion and Time Dimensions

Mateusz Urbańczyk, Wiktor Koźmiński, Krzysztof Kazimierczuk


alt

Diffusion-ordered multidimensional NMR spectroscopy is a valuable technique for the analysis of complex chemical mixtures. However, this method is very time-consuming because of the costly sampling of a multidimensional signal. Various sparse sampling techniques have been proposed to accelerate such measurements, but they have always been limited to frequency dimensions of NMR spectra. It is now revealed how sparse sampling can be extended to diffusion dimensions.

 


Page 3 of 5






Banner
Banner
Banner

Conferences organized

by us:


 

euromar 2017 logo

 


 

mmcebanner3

 


 

AUM4

 


We use cookies to improve our website and your experience when using it. Cookies used for the essential operation of the site have already been set.

I accept cookies from this site.