ISSN:
1573-5001
Keywords:
Cytokine
;
Leukaemia inhibitory factor
;
Isotope labelling
;
Heteronuclear NMR
;
Chemical shift assignments
;
Helices
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Abstract The chemical shift assignments and secondary structure of a murine–human chimera,MH35, of leukaemia inhibitory factor (LIF), a 180-residue protein of molecular mass 20 kDa,have been determined from multidimensional heteronuclear NMR spectra acquired on auniformly 13C,15N-labelled sample. Secondary structure elements were defined on the basisof chemical shifts, NH-CαH coupling constants, medium-range NOEs and the location ofslowly exchanging amide protons. The protein contains four α-helices, the relativeorientations of which were determined on the basis of long-range, interhelical NOEs. The fourhelices are arranged in an up-up-down-down orientation, as found in other four-helical bundlecytokines. The overall topology of MH35-LIF is similar to that of the X-ray crystallographicstructure for murine LIF [Robinson et al. (1994) Cell, 77, 1101–1116]. Differencesbetween the X-ray structure and the solution structure are evident in the N-terminal tail, wherethe solution structure has a trans-Pro17 compared with the cis-Pro17 found in the crystalstructure and the small antiparallel β-sheet encompassing residues in the N-terminus andCD loop in the crystal structure is less stable.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1018636018243
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