Comparison of the solution conformation and dynamics of antifreeze glycoproteins from Antarctic fish

Andrew N. Lane, Lisa M. Hays, Nelly Tsvetkova, Robert E. Feeney, Lois M. Crowe, John H. Crowe

Research output: Contribution to journalArticlepeer-review

45 Scopus citations

Abstract

The 1H- and 13C-NMR spectra of antifreeze glycoprotein fractions 1-5 from Antarctic have been assigned, and the dynamics have been measured using 13C relaxation at two temperatures. The chemical-shifts and absence of non- sequential 1H-1H NOEs are inconsistent with a folded, compact structure. 13C relaxation measurements show that the protein has no significant long- range order, and that the local correlation times are adequately described by a random coil model. Hydroxyl protons of the sugar residues were observed at low temperature, and the presence of exchange-mediated ROEs to the sugar indicate extensive hydration. The conformational properties of AFGP1-5 are compared with those of the previously examined 14-mer analog AFGP8 which contains proline residues in place of some alanine residues (Lane, A.N., L. M. Hays, R. E. Feeney, b M; Crowe; and J. H. Crowe. 1998. Protein Sci. 7:1555-1563). The infrared (IR) spectra of AFGP8 and AFGP1-5 in the amide I region are quite different. The presence of a wide distribution of backbone torsion angles in AFGP1-5 leads to a rich spectrum of frequencies in the IR spectrum, as interconversion among conformational states is slow on the IR frequency time scale. However, these transitions are fast on the NMR chemical shift time scales. The restricted motions for AFGP8 may imply a narrower distribution of possible φ, ψ angles, as is observed in the IR spectrum. This has significance for attempts to quantify secondary structures of proteins by IR in the presence of extensive loops.

Original languageEnglish
Pages (from-to)3195-3207
Number of pages13
JournalBiophysical Journal
Volume78
Issue number6
DOIs
StatePublished - Jun 2000

Bibliographical note

Funding Information:
This work was supported by the Medical Research Council of the UK and by National Institutes of Health Grant R01HL57810-01.

ASJC Scopus subject areas

  • Biophysics

Fingerprint

Dive into the research topics of 'Comparison of the solution conformation and dynamics of antifreeze glycoproteins from Antarctic fish'. Together they form a unique fingerprint.

Cite this