Unknown

Dataset Information

0

Reversibility of biotin-binding by selective modification of tyrosine in avidin.


ABSTRACT: The tight interaction between the vitamin biotin and the protein avidin is so strong (Ka approximately 10(15) M-1) that conditions which are usually sufficient for protein denaturation fail to dissociate the avidin-biotin complex. In order to form a reversible interaction between the two biomolecules, we have modified the binding-site tyrosine by nitration, thus reducing the pKa of the phenol group which forms a crucial hydrogen bond with the ureido group of biotin. At relatively low pH values (4-5), the resultant modified forms of avidin bind biotin with a very high association constant ( > 10(9) M-1). The modified avidins are thus capable of supporting stable, long-term binding of biotin or biotinylated macro-molecules. The latter molecules can be detached by increasing the pH of the medium or by introduction of excess levels of biotin at neutral pH. These findings demonstrate the importance of a single hydrogen bond for strong biotin binding. The new derivatives of avidin should be useful for applications whereby a reversible interaction between the four biotin-binding sites and biotin is desired, thus increasing the versatility of the avidin-biotin system for biotechnological application.

SUBMITTER: Morag E 

PROVIDER: S-EPMC1217322 | biostudies-other | 1996 May

REPOSITORIES: biostudies-other

Similar Datasets

| S-EPMC3383089 | biostudies-literature
| S-EPMC1131609 | biostudies-other
| S-EPMC10579862 | biostudies-literature
| S-EPMC1082904 | biostudies-literature
| S-EPMC5717103 | biostudies-literature
| S-EPMC1151383 | biostudies-other
| S-EPMC7711042 | biostudies-literature
| S-EPMC6473509 | biostudies-literature
| S-EPMC1222514 | biostudies-other
| S-EPMC1270186 | biostudies-other