A Caltech Library Service

A mathematical model for metal affinity protein partitioning

Suh, Sung-Sup and Arnold, Frances H. (1990) A mathematical model for metal affinity protein partitioning. Biotechnology and Bioengineering, 35 (7). pp. 682-690. ISSN 0006-3592. doi:10.1002/bit.260350705.

Full text is not posted in this repository. Consult Related URLs below.

Use this Persistent URL to link to this item:


A mathematical model of metal affinity partitioning has been derived and used to describe protein partitioning in Cu (II)PEG/dextran systems. A working model has been extended to account for inhibition, which for metal affinity extraction is the inhibition of protein‐metal binding by hydrogen ion. PEG/dextran partitioning experiments were performed on four proteins, tuna heart cytochrome c, Candida krusei cytochrome c, horse myoglobin, and sperm whale myoglobin. The partition coefficients for these proteins are increased by the addition of Cu (II)PEG‐IDA, due to the affinity between the chelated copper atom and metal‐coordinating histidine residues on the protein surface. The results of experiments to determine the effects of the number of binding sites on the protein, the copper concentration, and pH on partitioning are all well‐described by the mathematical model. The pK_a value of the metal binding site was determined to be 6.5, which is in the range of pK_a values commonly observed for surface histidines. The average association constant for the binding of Cu (II)PEG‐IDA to accessible histidines was found to be 4.5 × 10^3. This value is comparable to stability constants measured by conventional potentiometry techniques for analogous small complexes.

Item Type:Article
Related URLs:
URLURL TypeDescription
Arnold, Frances H.0000-0002-4027-364X
Additional Information:© 1990 John Wiley & Sons, Inc. Manuscript accepted: 07 August 1989.
Issue or Number:7
Record Number:CaltechAUTHORS:20180329-160928761
Persistent URL:
Official Citation:Suh, S. and Arnold, F. H. (1990), A mathematical model for metal affinity protein partitioning. Biotechnol. Bioeng., 35: 682-690. doi:10.1002/bit.260350705
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:85515
Deposited By: Tony Diaz
Deposited On:29 Mar 2018 23:26
Last Modified:15 Nov 2021 20:29

Repository Staff Only: item control page