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Functionalization of a protein surface with per‐ O ‐methylated β ‐cyclodextrin
Author(s) -
Kitagishi Hiroaki,
Kashiwa Kazuya,
Kano Koji
Publication year - 2012
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.21695
Subject(s) - chemistry , bovine serum albumin , hemin , iodoacetamide , surface modification , fluorescence , quenching (fluorescence) , stereochemistry , polymer chemistry , heme , organic chemistry , cysteine , chromatography , physics , quantum mechanics , enzyme
Per‐O‐methylated β‐cyclodextrin (CD) bearing an iodoacetamide group at the 6‐position was synthesized to functionalize protein surfaces. Bovine serum albumin (BSA) was quantitatively modified with the CD derivative by the S N 2 reaction of iodoacetamide with a cysteine residue (Cys34) on the BSA surface. The resultant CD‐functionalized BSA (BSA‐CD) spontaneously dimerized upon addition of an anionic tetraarylporphyrin (TPPS) through the supramolecular 1:2 complexation between TPPS and CD on the protein surface. The BSA‐CD/TPPS complex further complexed with ferric protoporphyrin IX (hemin) in the hydrophobic pockets of albumin to form a hemin/BSA‐CD/TPPS ternary complex in which static fluorescence quenching occurred owing to intramolecular electron transfer from the photoexcited TPPS to hemin. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 11–20, 2012.