Biomedical subjects

Konstantin Pervushin

Publications and source records attributed to Konstantin Pervushin.

21 records · Page 2Linked to original sources

PubMed2002

Longitudinal (1)H relaxation optimization in TROSY NMR spectroscopy.

A general method to enhance the sensitivity of the multidimensional NMR experiments performed at high-polarizing magnetic field via the significant reduction of the longitudinal proton relaxation times is described. The method is based on the use of two vast pools of "thermal bath" 1H spins residing on hydrogens covalently attached to carbon and oxygen atoms in 13C,15N labeled and fully protonated or fractionally deuterated proteins to uniformly enhance longitudinal relaxation of the 1HN spins and concomitantly the sensitivity of multipulse NMR experiments. The proposed longitudinal relaxation optimization is implemented in the 2D [15N,1H]-LTROSY, 2D [15N,1H]-LHSQC and 3D LTROSY-HNCA experiments yielding the factor 2-2.5 increase of the maximal signal-to-noise ratio per unit time at 600 MHz. At 900 MHz, the predicted decrease of the 1HN longitudinal relaxation times can be as large as one order of magnitude, making the proposed method an important tool for protein NMR at high magnetic fields.

Bacillus subtilis↗

PubMed2002

NMR structure of the heme chaperone CcmE reveals a novel functional motif.

The concept of metal chaperones involves transient binding of metallic cofactors by specific proteins for delivery to enzymes in which they function. Metal chaperones thus provide a protective, as well as a transport, function. We report the first structure of a heme chaperone, CcmE, which comprises these two functions. We propose that the covalent attachment of heme to an exposed histidine occurs after heme binding at the surface of a rigid molecule with a flexible C-terminal domain. CcmE belongs to a family of proteins with a specific fold, which all share a function in delivery of specific molecular cargo.

Amino Acid Motifs↗

PubMed2002

TROSY experiment for refinement of backbone psi and phi by simultaneous measurements of cross-correlated relaxation rates and 3,4J(H alpha HN) coupling constants.

The TROSY principle has been introduced into a HNCA experiment, which is designed for measurements of the intraresidual and sequential H(alpha)-C(alpha)/H(N)-N dipole/dipole and H(alpha)-C(alpha)/N dipole/CSA cross-correlated relaxation rates. In addition, the new experiment provides values of the (3,4)J(H alpha HN) coupling constants measured in an E.COSY manner. The conformational restraints for the psi and phi angles are obtained through the use of the cross-correlated relaxation rates together with the Karplus-type dependencies of the coupling constants. Improved signal-to-noise is achieved through preservation of all coherence transfer pathways and application of the TROSY principle. The application of the [(15)N,(13)C]-DQ/ZQ-[(15)N,(1)H]-TROSY-E.COSY experiment to the 16 kDa apo-form of the E. coli Heme Chaperon protein CcmE is described. Overall good agreement is achieved between psi and phi angles measured with the new experiment and the average values determined from an ensemble of 20 NMR conformers.

Bacterial Outer Membrane Proteins↗