+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Synchrotron SAXS studies on the structural stability of Carcinus aestuarii hemocyanin in solution



Synchrotron SAXS studies on the structural stability of Carcinus aestuarii hemocyanin in solution



Biophysical Journal 85(4): 2661-2672



The effect of GuHCl and of NaCl on the structural properties of the hemocyanin (Hc) from Carcinus aestuarii has been studied by small angle x-ray scattering (SAXS) using synchrotron radiation. SAXS data collected as a function of perturbant concentration have been used to analyze conformational states of hexameric holo and apoHc as well as the holo and apoforms of the monomeric subunit CaeSS2. In the case of the holoprotein in GuHCl, two concentration domains were identified: at lower concentration, the perturbant induces aggregation of Hc molecules, whereas at higher concentration the aggregates dissociate with concomitant denaturation of the protein. In contrast, with apoHc the denaturation occurs at rather low GuHCl, pointing to an important effect of the active site bound copper for the stabilization of Hc tertiary structure. The effects of NaCl are similar to those of GuHCl as far as CaeSS2 is concerned, namely oligomerization precedes denaturation, whereas in the case of the hexameric form no aggregation occurs. To improve data analysis, on the basis of the current models for Hc monomers and oligomers, the fraction of each aggregation state and/or unfolded protein has been determined by fitting experimental SAXS curves with form factors calculated from Monte Carlo methods. In addition, a global analysis has been carried out on the basis of a thermodynamic model involving an equilibrium between a monomer in a nativelike and denatured form as well as a class of equilibria among the monomer and other aggregates.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 011436850

Download citation: RISBibTeXText

PMID: 14507729

DOI: 10.1016/s0006-3495(03)74689-x


Related references

SAXS investigation on the temperature dependence of the conformation of Carcinus aestuarii 5S hemocyanin subunit. Journal of Molecular Structure 475(1): 73-82, 1999

Spectroscopic properties of Carcinus aestuarii hemocyanin and its structural subunits. Spectrochimica Acta Part A Molecular and Biomolecular Spectroscopy 55(14): 2927-2934, 1999

Spectroscopic properties of Carcinus aestuarii hemocyanin and its structural subunits. Spectrochimica Acta. Part A Molecular and Biomolecular Spectroscopy 55a(14): 2927-2934, 1999

Contribution of the copper ions in the dinuclear active site to the stability of Carcinus aestuarii hemocyanin. Archives of Biochemistry and Biophysics 439(1): 42-52, 2005

Structural role of the copper ions in the dinuclear active site of Carcinus aestuarii hemocyanin. Micron 35(1-2): 43-44, 2004

Carbohydrate composition of Carcinus aestuarii hemocyanin. Archives of Biochemistry and Biophysics 389(2): 153-158, 2001

Fluorescence spectroscopy of the tryptophan microenvironment in Carcinus aestuarii hemocyanin. Zeitschrift fuer Naturforschung C Journal of Biosciences ember- 57(11-12): 1084-1091, 2002

Fluorescence spectroscopy of the tryptophan microenvironment in Carcinus aestuarii hemocyanin. Zeitschrift für Naturforschung. C Journal of Biosciences 57(11-12): 1084-1091, 2002

Subunits composition and allosteric control in Carcinus aestuarii hemocyanin. European Journal of Biochemistry 256(2): 350-358, 1998

Application of microsatellites for the study of genetic differentiation of the bioindicator Carcinus aestuarii Applicazione di microsatelliti per lo studio del differenziamento genetico nel bioindicatore Carcinus aestuarii. Biologia Marina Mediterranea 132: 324-325, 2006

Guanidinium chloride induced unfolding of a hemocyanin subunit from Carcinus aestuarii I. Apo form. Biochimica et Biophysica Acta 1597(1): 42-50, 2002

Structure of hemocyanin subunit CaeSS2 of the crustacean Mediterranean crab Carcinus aestuarii. Journal of Biochemistry 138(3): 303-312, 2005

Guanidinium chloride induced unfolding of a hemocyanin subunit from Carcinus aestuarii II. Holo form. Biochimica et Biophysica Acta 1597(1): 51-59, 2002

The binding of azide to copper-containing and cobalt-containing forms of hemocyanin from the mediterranean crab Carcinus aestuarii. European Journal of Biochemistry 247(2): 688-694, 1997

Anthropic impact on the lagoon environment effects on the adaptative plasticity of Carcinus aestuarii Impatto antropico sugli ecosistemi lagunari effetti plasticita adattativa di Carcinus aestuarii. Biologia Marina Mediterranea 132: 244-245, 2006