Biomedical subjects

Nagarajan Murali

Publications and source records attributed to Nagarajan Murali.

3 recordsLinked to original sources

PubMed2006

IDEAL-A fast single scan method for X pulse width calibration.

In line with the recent development of the rapid single scan technique to calibrate proton flip angle, a new method that allows calibration of X-nucleus pulse width in a single scan is presented. The method involves observation of the anti-phase coherence of a proton coupled to a hetero-nuclear X-spin with nutation pulses applied at the X-spin resonance frequency in a gated decoupling experiment. The X-spin nutation causes the well-known illusions of decoupling, enabling estimation of rf amplitude level and the method is, thus, dubbed as IDEAL.

Algorithms↗

PubMed2005

Spectral unraveling by space-selective Hadamard spectroscopy.

Spectral unraveling by space-selective Hadamard spectroscopy (SUSHY) enables recording of NMR spectra of multiple samples loaded in multiple sample tubes in a modified spinner turbine and a regular 5mm liquids NMR probe equipped with a tri-axis pulsed field gradient coil. The individual spectrum from each sample is extracted by adding and subtracting data that are simultaneously obtained from all the tubes based on the principles of spatially resolved Hadamard spectroscopy. The well-known Hadamard spectroscopy has been applied for spatial selection and the method utilizes standard configuration of NMR instrument hardware. The SUSHY method can be easily incorporated in multi-dimensional multi-tube NMR experiments. This method combines the excitation multiplexing, natural advantage of FTNMR, and sample multiplexing and offers high-throughput by reducing the total experimental time by up to a factor of four in a 4-tube mode.

Equipment Design↗

PubMed2005

NMR analyses of the activation of the Arp2/3 complex by neuronal Wiskott-Aldrich syndrome protein.

The VCA domain of the neuronal Wiskott-Aldrich syndrome protein (N-WASP) is a potent activator of the Arp2/3 complex, a 240 kDa heteroheptameric actin-nucleating assembly. We used site-directed spin labeling of N-WASP peptides in conjunction with methyl-TROSY spectra of the intact, selectively labeled Arp2/3 complex to identify regions of the VCA that are proximal to the ARPC3 subunit of the assembly. We also cross-linked CA peptides to the Arp3, Arp2, ARPC1, and ARPC3 subunits. The combined data suggest that the extreme C-terminus of the A region and the C-terminus of the C region of N-WASP are proximal to ARPC3. These results have implications for the mechanism of Arp2/3 complex activation by VCA peptides. This study also demonstrates the utility of NMR spectroscopy for studying ligand binding events in large, asymmetric, macromolecular assemblies.

Actin-Related Protein 2-3 Complex↗