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Science 27 December 1968:
Vol. 162. no. 3861, pp. 1487 - 1489
DOI: 10.1126/science.162.3861.1487
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Articles

Photoregulation of an Enzymic Process by Means of a Light-Sensitive Ligand

H. Kaufman 1, S. M. Vratsanos 1, and B. F. Erlanger 1

1 Department of Microbiology, College of Physicians and Surgeons, Columbia University, New York 10032

A specific inactivator of chymotrypsin, p-azophenyldiphenylcarbamyl chloride, exists as two geometric isomers, cis and trans, which are interconvertible by means of light. The cis-isomer is five times more reactive than the more stable trans-isomer, and is obtained by exposure of the latter to light of 320 nanometer wavelength. The trans-isomer can be regained by exposure of the cis-isomer to light of 420 nanometer wavelength. This interconversion can be made to occur in aqueous solution in the presence of the enzyme under conditions in which the trans-isomer reacts relatively slowly with chymotrypsin. Thus, it is possible to regulate the rate of inactivation of chymotrypsin by using light of the appropriate wavelength. This system is presented as a model for some of the light-sensitive metabolic systems present in living organisms.


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Photoregulated ion binding.
M Blank, L. Soo, H. Wassermann, and B. Erlanger (1981)
Science 214, 70-72
   Abstract »    PDF »


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Science. ISSN 0036-8075 (print), 1095-9203 (online)