title: Using wavelet de-noised spectra in NMR screening.
abstract: Principal component analysis (PCA) is a commonly used algorithm in multivariate analysis of NMR screening data. PCA substantially reduces the complexity of data in which a large number of variables are interrelated. For series of NMR spectra obtained for ligand binding, it is commonly used to visually group spectra with a similar response to ligand binding. A series of filters are applied to the experimental data to obtain suitable descriptors for PCA which optimize computational efficiency and minimize the weight of small chemical shift variations. The most common filter is bucketing where adjacent points are summed to a bucket. To overcome some inherent disadvantages of the bucketing procedure we have explored the effect of wavelet de-noising on multivariate analysis, using a series of HSQC spectra of proteins with different ligands present. The combination of wavelet de-noising and PCA is most efficient when PCA is applied to wavelet coefficients. This new algorithm yields good clustering and can be applied to series of one- or two-dimensional spectra.
authors.affiliation: Center for Biomolecular Magnetic Resonance (BMRZ), Institute of Biophysical Chemistry, J.W. Goethe University, Marie-Curie-Str. 9, 60439 Frankfurt, Germany.
authors.forename: Nikola
authors.initials: N
authors.lastname: Trbovic
authors.forename: Felician
authors.initials: F
authors.lastname: Dancea
authors.forename: Thomas
authors.initials: T
authors.lastname: Langer
authors.forename: Ulrich
authors.initials: U
authors.lastname: Günther
mesh_terms: D006859:Hydrogen; D008024:Ligands; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011506:Proteins / Q000737:chemistry*
chemical_list: D008024:Ligands; D009587:Nitrogen Isotopes; D011506:Proteins; D006859:Hydrogen