title: A simple procedure for the photoregulation of chymotrypsin activity.
abstract: A convenient and rapid method for the photo-regulation of the proteolytic enzyme alpha-chymotrypsin is described. When alpha-chymotrypsin is coated with photolytic 1-(2-nitrophenyl)ethanol residues this not only markedly reduces the capability of the enzyme to digest both of the small substrates N-benzoyl-L-tyrosine ethyl ester and N-succinyl-L-phenylalanine p-nitroanilide, but also completely inhibits the enzyme's proteolytic activity. The inactivated alpha-chymotrypsin can then be reactivated under physiological conditions, when and where it is required, by exposure to UV-A light. These results further demonstrate that 1-(2-nitrophenyl)ethanol coated proteins can often be used as light sensitive biological switches as a simple alternative to site directed procedures.
authors.affiliation: Diagnostic and Therapeutic Technologies, School of Clinical and Laboratory Sciences, University of Newcastle upon Tyne, The Medical School, Newcastle upon Tyne, NE2 4HH, UK. C.H.Self@ncl.ac.uk
authors.forename: Stephen
authors.initials: S
authors.lastname: Thompson
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Fawcett
authors.forename: Lesley B
authors.initials: LB
authors.lastname: Pulman
authors.forename: Colin H
authors.initials: CH
authors.lastname: Self
mesh_terms: D000818:Animals; D002417:Cattle; D002918:Chymotrypsin / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000528:radiation effects; D004789:Enzyme Activation / Q000187:drug effects; D000431:Ethanol / Q000031:analogs & derivatives* / Q000494:pharmacology; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000494:pharmacology*; D010649:Phenylalanine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D010777:Photochemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D009578:Nitrobenzenes; C011358:Suphepa; D012710:Serum Albumin, Bovine; C063593:1-(2-nitrophenyl)ethanol; C006716:benzoyltyrosine ethyl ester; D000431:Ethanol; D014443:Tyrosine; D010649:Phenylalanine; D002918:Chymotrypsin; C117608:alpha-chymotrypsin