ISSN:
0947-6539
Keywords:
boronic acids
;
heme proteins
;
molecular recognition
;
myoglobin
;
saccharides
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Phenylboronic acid groups as sugar recognition sites were successfully introduced into native myoglobin by a cofactor-reconstitution method. Spectrophotometric pH titration demonstrated the sugar-induced pKa shift of the H2O coordinated to the heme center of the semisynthetic myoglobin bearing phenyl-boronic acids (met-Mb(PhBOH)2). By means of circular dichroism (CD) and paramagnetic 1H NMR spectroscopies, it was proven that sugars that were bound to phenylboronic acid sites induced the rearrangement of the heme crevice to reinforce the heme cofactor-apoprotein interactions. The structural changes that were induced by the binding of sugars subsequently enhanced the dioxygen storage activity of Mb(PhBOH)2. Such sugar-induced structural and functional changes did not occur for other modified Mbs that had no sugar-recognition units. Interestingly, a randomly modified Mb with phenylboronic acid units did not show any sugar response. In Mb(PhBOH)2, the information from the sugar-binding event was efficiently transmitted to the active center, so that the activity was efficiently altered upon sugar binding. In conclusion, the active site specific incorporation of molecular recognition units as nonnatural functional molecules can provide a novel strategy for the design of stimuli-responsive semisynthetic proteins.
Additional Material:
4 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19970030707
