A Reliable Switched Angle Spinning (SAS) Probe with Gradients (PFG) for Proteins in Solid-State NMR

A Reliable Switched Angle SpinningSASProbe with GradientsPFGfor Proteins in Solid State NMR AbstractSolid state NMRssNMRbiotechnology is emerging as an alternative method of choice for highresolution structure determination for integral membrane proteinsIMPsssNMR provides a unique platform to investigate protein dynamicsand functional studies of wide range of biomolecules in their supramolecular assembliesWhile there exists a suite of magic angle spinningMASand oriented sampleOSsolid state NMR experiments for structural characterization of smalland medium sized proteinsthese methods face several challenges in larger systemsCentral to the challenges are NMR sensitivity and resolutionFast MAS andH detected experiments improve sensitivity but are limited by sample volume and relatively poor resolution over small isotropic chemical shift dispersionAdditionallythe efficiency of MAS experiments depends largely on through bond and through space coupling constantssolvent suppressionand coherence pathways selection during rotor synchronized multi pulse applicationsThey also suffer from sensitivity loss due to local and global motions in proteinsOn the other handstatic OS NMR experiments in membrane proteins improve resolution by measuring anisotropic shifts and heteronuclear dipolar couplingsbut are limited to dilute spins and low gammaN detection onlyIt has long been realized that unification of MAS and OS has the ability to widen the spectroscopic applications to large globular and membrane proteinsSwitched angle spinningSASprobes unify MASdynamic angle spinningDASand variable angle spinningVAStechniques in ssNMRand potentially correlate isotropic and anisotropic shifts couplings in more than one Fourier dimensionSuch powerful techniques are still far from practical usebecause SAS probes in the past have suffered from the lack of reliability due to hardware failures such as the survival of multi channel rf leadsrf coil performance including Bfield strength and homogeneityspinning stabilityand lastly rapid reorientation and accurate angle reproducibilityTechnical difficulties and engineering challenges thus far have limited the probe technology to only two frequency channelsThis proposal seeks funding for the development of a reliable switched angle spinning probe devoid of previously encountered hardware related issues and compatible with high power pulsed field gradientsThe Phase I probe will have fixed tuning frequencies forHCandN nuclei atT for biological applications onlyThe phase II probe will advance the technology with two broad band low frequency channels to accommodate other functional elements important in biology and chemistryAdditionallythe triple channel probe will be compatible with standard three axis gradient coils in order to enable gradient enhanced spectroscopic methodsdiffusion NMRand micro imaging capabilities in solid stateThe advent of such a probe will enhance our ability to develop novel methods for NMR study of proteins and screening of therapeutic drugs A Reliable Switched Angle SpinningSASProbe with GradientsPFGfor Proteins in Solid State NMR NarrativeWorldwide thousands of laboratories in academia and industry use solid state NMRwith a majority of the applications driven by the need for structure and function determination in biological macromoleculesThe availability of a highly novel add on accessoryan SAS PFG probefor existing ssNMR systems that can dramatically improve the quality of the needed informationand obtain that information quicklycan be transformative in certain areas of health related researchincluding development of drugs for Alzheimer s DiseaseThe instrument that will come from this proposed effort is expected to provide a valuable business opportunity for the companywith ripple effects extending throughout its community