TY - JOUR
T1 - Host-guest interactions of cyclodextrins and metalloporphyrins
T2 - Supramolecular building blocks toward artificial heme proteins
AU - Zhou, Huchen
AU - Groves, John Taylor
PY - 2004
Y1 - 2004
N2 - Cyclodextrins are versatile building blocks for a variety of macromolecules due to the inclusion complexes that are formed with hydrophobic organic molecules. Cyclodextrin-porphyrin interactions are of particular interest since cyclodextrins can serve as a non-covalent binding pocket while metalloporphyrins could serve as the heme analogs in the construction of heme protein model compounds. Various approaches to the design and assembly of biomimetic porphyrin constructs are compared and contrasted in this minireview with a particular emphasis on self-assembled and porphyrin-cyclodextrin systems. Several recent advances from our laboratories are described in this context. A sensitive fluorescent binding probe, 6A-N-dansyl-permethylated-β- cyclodextrin (Dan-NH-TMCD), was found to form 2:1 complexes with the meso-tetraphenylporphyrins Mn(III)TCPP, Mn(III)TPPS and Mn(III)TF 4TMAP with high binding constants. A perPEGylated cyclodextrin, heptakis(2,3,6-tri-O-2-(2-(2-methoxyethoxy)ethoxy)ethyl)-β-cyclodextrin (TPCD), has been shown by 1H NMR spectroscopy to forma a 1:1 complex with H2TCPP with a binding constant above 108 M -1. Such a strong binding constant is the largest found for a 1:1 complex between a monomeric cyclodextrin and a guest. TPCD was also found to bind Mn(III)TCPP with a binding constant of 1.2 × 106 M -1. A novel, self-assembled hemoprotein model, hemodextrin is also described. The molecular design is based on a PEGylated cyclodextrin scaffold that bears both a heme-binding pocket and an axial ligand that binds an iron porphyrin. The binding constant for Fe(III)TPPS (iron(III) meso-tetra(4- sulfonatophenyl)porphyrin) by py-PPCD was determined to be 2 × 10 6 M-1. The pyridyl nitrogen of py-PPCD was shown to ligate to the iron center by observing signal changes in the Fe(II)-porphyrin 1H NMR spectrum. This hemodextrin ensemble, a minimalist myoglobin, was shown to bind dioxygen reversibly and to form a stable ferryl species.
AB - Cyclodextrins are versatile building blocks for a variety of macromolecules due to the inclusion complexes that are formed with hydrophobic organic molecules. Cyclodextrin-porphyrin interactions are of particular interest since cyclodextrins can serve as a non-covalent binding pocket while metalloporphyrins could serve as the heme analogs in the construction of heme protein model compounds. Various approaches to the design and assembly of biomimetic porphyrin constructs are compared and contrasted in this minireview with a particular emphasis on self-assembled and porphyrin-cyclodextrin systems. Several recent advances from our laboratories are described in this context. A sensitive fluorescent binding probe, 6A-N-dansyl-permethylated-β- cyclodextrin (Dan-NH-TMCD), was found to form 2:1 complexes with the meso-tetraphenylporphyrins Mn(III)TCPP, Mn(III)TPPS and Mn(III)TF 4TMAP with high binding constants. A perPEGylated cyclodextrin, heptakis(2,3,6-tri-O-2-(2-(2-methoxyethoxy)ethoxy)ethyl)-β-cyclodextrin (TPCD), has been shown by 1H NMR spectroscopy to forma a 1:1 complex with H2TCPP with a binding constant above 108 M -1. Such a strong binding constant is the largest found for a 1:1 complex between a monomeric cyclodextrin and a guest. TPCD was also found to bind Mn(III)TCPP with a binding constant of 1.2 × 106 M -1. A novel, self-assembled hemoprotein model, hemodextrin is also described. The molecular design is based on a PEGylated cyclodextrin scaffold that bears both a heme-binding pocket and an axial ligand that binds an iron porphyrin. The binding constant for Fe(III)TPPS (iron(III) meso-tetra(4- sulfonatophenyl)porphyrin) by py-PPCD was determined to be 2 × 10 6 M-1. The pyridyl nitrogen of py-PPCD was shown to ligate to the iron center by observing signal changes in the Fe(II)-porphyrin 1H NMR spectrum. This hemodextrin ensemble, a minimalist myoglobin, was shown to bind dioxygen reversibly and to form a stable ferryl species.
KW - Biomimetic
KW - Heme
KW - Host-guest
KW - Iron porphyrin
KW - Manganese porphyrin
KW - P450
UR - http://www.scopus.com/inward/record.url?scp=3342988352&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=3342988352&partnerID=8YFLogxK
U2 - 10.1142/s108842460400012x
DO - 10.1142/s108842460400012x
M3 - Short survey
AN - SCOPUS:3342988352
SN - 1088-4246
VL - 8
SP - 125
EP - 140
JO - Journal of Porphyrins and Phthalocyanines
JF - Journal of Porphyrins and Phthalocyanines
IS - 1-3
ER -