Multiple wavelength Anomalous

A teclmique that employs principles similar to those of isomorphous replacement is multiple-wavelength anomalous diffraction (MAD) [27]. The expression for the atomic scattering factor in equation (B1.8.2h) is strictly accurate only if the x-ray wavelength is well away from any characteristic absorption edge of the element, in which case the atomic scattering factor is real and Filiki) = Fthkl V- Since the diffracted... 

Several structurally different types of HNLs occur in nature, which likely originated hy convergent evolution from different ancestral proteins. The enzyme from almond (PaHNL) was first crystallized in 1994 and the structure was solved by multiple wavelength anomalous dispersion of a mercury derivative. The first 3D structure analysis of PaHNL was performed in 2001. ° (7 )-PaHNL from almond uses FAD as cofactor and is related to oxidoreductases it exhibits HNL activity only in the oxidized form of FAD." ... 

Ealick, S.E. (2000) Advances in multiple wavelength anomalous diffraction crystallography, Curr. Opin. Chem. Biol., 4, 495-499. 

The multiple-wavelength anomalous diffraction method (MAD) relies upon sufficiently strong anomalously scattering atoms in the protein structure itself In this method, diffraction data must be collected at a number of different wavelengths, usually requiring data collection with... 

From a relatively small begiiming, nearly two decades ago (Guss et al., 1988 Murthy et al., 1988 Hendrickson et al., 1988, 1989), phase calculation using Multiple-wavelength Anomalous Diffraction (MAD) data has become more widespread and generally used. There are many reviews that cover diverse aspects of the process (Hendrickson, 1991 Smith, 1991 Ogata, 1998 Ealick, 2000). This review will concentrate on the most recent developments and experimental details, and is essentially an update to the author s earlier review (Krishna Murthy, 1996). 

Krishna Murthy H. M. (1996). The use of multiple wavelength anomalous diffraction in ab initio phase determination. Method Mol. Biol. 56,127-152. 

Alternative methods of solving the phase problem are also used now. When a transition metal such as Fe, Co, or Ni is present in the protein, anomolous scattering of X-rays at several wavelengths (from synchrotron radiation) can be used to obtain phases. Many protein structures have been obtained using this multiple wavelength anomalous diffraction (MAD phasing) method.404 407 408 Selenocysteine is often incorporated into a protein that may be produced in... 

The X REL1 crystal structure, which consists of residues 52-316 corresponding to the N-terminal domain, was resolved using the SeMet multiple-wavelength anomalous dispersion method (9). The selenomethionines used for this method should be replaced with methionines to obtain the original form of the protein for simulations (see Note 2). 

Currently, use of selenium methionine, recombinant protein crystals, or crystals of wild type protein into which have been introduced heavy atom anomalous scatterers, has made single and multiple wavelength anomalous scattering the method of choice for phase determination. In addition, the ways it can be used, and the increasing opportunities for its application are dramatically expanding its popularity. 

M. Helliwell, J.R. Helliwell, V. Kaucic, N.Z. Logar, L. Barba, E. Busetto, and A. Lausi, Determination of the Site of Incorporation of Cobalt in CoZnPO-CZP by Multiple-wavelength Anomalous-dispersion Crystallography. Acta Crystallogr., Sect. B Struct. 

Energy-dispersive mode for multiple wavelength anomalous... 

MWPCs have been successfully used at LURE and Stanford for multiple wavelength anomalous dispersion phasing measurements (see chapter 9). An MWPC has also been used to record Laue diffraction patterns at VEPP-3 (Gaponov et al 1989a,b,c). 

The more automatic solution of crystal structures using variable or multiple wavelength anomalous scattering measurements is an important development especially when conventional, isomorphous, heavy atom derivatives cannot be made. The phasing power of the anomalous scattering component of specific atoms can be fully optimised with SR. 

Multiple wavelength anomalous dispersion based on selenomethionines introduced by genetic engineering [90H1]. PROFFT 0.198 0.015 A 0.034 A 1... 

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