Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 39: 202-208, 1993;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kragh-Hansen, U.
Right arrow Articles by Vorum, H.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kragh-Hansen, U.
Right arrow Articles by Vorum, H.

Clinical Chemistry, Vol 39, 202-208, Copyright © 1993 by American Association for Clinical Chemistry

Quantitative analyses of the interaction between calcium ions and human serum albumin

U Kragh-Hansen and H Vorum
Institute of Medical Biochemistry, University of Aarhus, Denmark.

We examined the suitability of nine organic buffers for studying calcium binding to albumin by equilibrium dialysis. Results obtained with defatted human serum albumin showed that 4-(2-hydroxyethyl)-1- piperazineethanesulfonic acid (HEPES) and 2- ([tris(hydroxymethyl)methyl] amino)ethanesulfonic acid were superior. Scatchard analysis of the experimental data from an extensive study performed in HEPES at pH 7.4 and 20 degrees C revealed (putting n(i) = 1, i = 1-4) k1 = 367 L/mol, k2 = 314 L/mol, k3 = 291 L/mol, and k4 = 179 L/mol. The very weak binding was characterized as n5 = 10 and k5 = 40 L/mol. The results were also analyzed in terms of stoichiometric association constants. The constants K1 and K2 were calculated to be 1513 and 647 L/mol, respectively, whereas the other constants were considered undeterminable. pH studies showed that in the interval 6.8- 7.4, binding was not influenced by changes in acidity. Increasing pH to above the physiological value resulted in increased binding. At pH 8.0, k1 was increased almost fourfold, whereas k2 and k3 were approximately doubled. These findings indicate that the neutral to basic transition is important for the calcium-binding properties of albumin. The transition is a reversible, gradual conformational change of the protein at pH 6-9.


The following articles in journals at HighWire Press have cited this article:


Home page
 MicrobiologyHome page
J. Kim, K. Ahn, S. Min, J. Jia, U. Ha, D. Wu, and S. Jin
Factors triggering type III secretion in Pseudomonas aeruginosa
Microbiology, November 1, 2005; 151(11): 3575 - 3587.
[Abstract] [Full Text] [PDF]

Home page
 Hum ReprodHome page
N. Cirelli, P. Lebrun, C. Gueuning, J. Delogne-Desnoeck, A.-M. Vanbellinghen, G. Graff, and S. Meuris
Physiological concentrations of albumin stimulate chorionic gonadotrophin and placental lactogen release from human term placental explants
Hum. Reprod., March 1, 2001; 16(3): 441 - 448.
[Abstract] [Full Text] [PDF]

Home page
 J. Biol. Chem.Home page
M. S. Nielsen, H. Vorum, E. Lindersson, and P. H. Jensen
Ca2+ Binding to alpha -Synuclein Regulates Ligand Binding and Oligomerization
J. Biol. Chem., June 15, 2001; 276(25): 22680 - 22684.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1993 by the American Association for Clinical Chemistry.