title: Copper complexes of (-)-epicatechin gallate and (-)-epigallocatechin gallate act as inhibitors of Ribonuclease A.
abstract: Green tea polyphenols, which have the ability to inhibit angiogenesis, form complexes with Cu(II), a known potent stimulator of blood vessel proliferation. Copper complexes of (-)-epicatechin gallate and (-)-epigallocatechin gallate were found to inhibit the enzymatic activity of Ribonuclease A (RNase A) as revealed by an agarose gel based assay and urea denatured gel electrophoresis. The copper complexes were found to be non-competitive inhibitors of RNase A with inhibition constants in the micromolar range. Changes in the secondary structure of the protein are found to occur due to the interaction as revealed from Fourier transform infrared and circular dichroism studies.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
authors.forename: Kalyan Sundar
authors.initials: KS
authors.lastname: Ghosh
authors.forename: Tushar Kanti
authors.initials: TK
authors.lastname: Maiti
authors.forename: Abhishek
authors.initials: A
authors.lastname: Mandal
authors.forename: Swagata
authors.initials: S
authors.lastname: Dasgupta
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry* / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D007700:Kinetics; D012259:Ribonuclease, Pancreatic / Q000037:antagonists & inhibitors*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D004791:Enzyme Inhibitors; D003300:Copper; D002392:Catechin; C062669:epicatechin gallate; C045651:epigallocatechin gallate; D012259:Ribonuclease, Pancreatic