Download or read book On the Determination of Three-dimensional Protein Structures by Nuclear Magnetic Resonance Methods written by Per J. Kraulis and published by . This book was released on 1989 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last 10 years, nuclear magnetic resonance (NMR) methods have been developed to determine the three-dimensional structures of small proteins. This thesis reviews these methods and discusses their limitations. The assignment of the NMR spectrum of a protein is a necessary, bbut not sufficient, requirement for the determinetion of its structure by NMR methods.For this purpose, an interactive graphics program ANSIG has been developed. Spectrum contours can be viewed, and cross peaks extracted, connested and assigned. Assignment lists and distance restraints lists derived from NOESY cross peak intensities can be produced. A novel algorithm for the calculation of three-dimensional protein structures from inter-proton distance restraints derived ,from NMR data has been implemented in the program NOEDIA. A data base of crystallographically determined protein structured is searched for fragments that fit the data and the protein structure is built from them. Cecropin A, an antibacterial peptide from the giant silk moth HYALOPHORA CECROPIA, was investigated in a solution containing 15% hexafluoroisopropyl alchohol. The three-dimensional structure of the 37-residue peptide was computed from the NMR data ba the simulated dynamical annealing method. It consists of two amphiphatic a-helical regions 5-21 and 24-37, whose relative orientation could not be defined. The cellulases of the filamentous fungus TRICHODERMA REESEI contain a strongly conserved small terminal domain, which is the N-terminal in two of them and C-terminal in the other two. The structure of a synthetic 36-residue peptide corresponding to the C-terminal domain of cellobiohydrolase I was determined grom NMR data using a hybrid distance geometry-dynamic simulated annealing method. The molecule is wedge-shaped and consists of an irregular triplestranded anti-parallel B-sheet. The structure is very well defined due to extensive stereospecific assignments and permits analysis of a number of side chain interactions. The first example of a 3D NMR spectrum of a protein is presented. The combination of two 2D experiments into a 3D experiment facilitates cross peak assignment and potentially increases the size of proteins amenable to structure determination ba NMR.