132l
From Proteopedia
STRUCTURAL CONSEQUENCES OF REDUCTIVE METHYLATION OF LYSINE RESIDUES IN HEN EGG WHITE LYSOZYME: AN X-RAY ANALYSIS AT 1.8 ANGSTROMS RESOLUTION
Overview
Chemical modification of proteins has been and continues to be an important biochemical tool for the study of protein structure and function. One such type of approach has been the reductive methylation of lysine residues. In order to address the consequences of such methylation on the crystallization and structural properties of a protein, the three-dimensional structure of hen egg white lysozyme in which all lysine residues have been alkylated has been determined and refined to a nominal resolution of 1.8 A and a crystallographic R factor of 17.3%. Crystals used in the investigation were grown from 1.5-1.8 M MgSO4 and 50 mM Tris at pH 8.0 and belonged to the space group P2(1)2(1)2(1) with unit cell dimensions of a = 30.6 A, b = 56.3 A, c = 73.2 A, and one molecule per asymmetric unit. It was not possible to grow crystals of the modified lysozyme under the conditions normally employed for the hen egg white protein. Overall, the three-dimensional structures of the native lysozyme and the modified protein are very similar with only two surface loops differing to any significant extent. Specifically, the positions of the alpha-carbons for these two forms of the protein, excluding the surface loops, superimpose with a root-mean-square value of 0.40 A. The magnitude of the structural changes observed between the modified an unmodified forms of lysozyme is similar to that seen when an identical protein structure is solved in two different crystalline lattices.(ABSTRACT TRUNCATED AT 250 WORDS)
About this Structure
132L is a Single protein structure. Full crystallographic information is available from OCA.
Reference
Structural consequences of reductive methylation of lysine residues in hen egg white lysozyme: an X-ray analysis at 1.8-A resolution., Rypniewski WR, Holden HM, Rayment I, Biochemistry. 1993 Sep 21;32(37):9851-8. PMID:8373783 Page seeded by OCA on Fri May 2 09:28:52 2008
