Modulation of a proteolytic enzyme activity by means of photochromic inhibitor

✍ Scribed by C. Amato; A. Fissi; L. Vaccari; E. Balestreri; O. Pieroni; R. Felicioli

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 404 KB
• Volume: 28
• Category: Article
• ISSN: 1011-1344
• DOI: 10.1016/1011-1344(94)07091-2

✦ Synopsis

On the basis of the known mechanism of the inhibition of a leaf proteinase by polycationic compounds we have synthesized a molecule in which two primary amino groups are spaced by an azobenzene moiety. The azo compound kept in the dark at room temperature is in the planar trans configuration. The trans--cis photoisomerization cycle is accomplished by irradiating the azo compound at 340 and 417 nm for the forward and back reactions respectively. The trans isomer was found to be a competitive inhibitor of the proteinase, whereas the cis isomer in the same concentration range did not inhibit the enzyme. This could be attributed to the different geometry and polarity of the two photoisomers. The modulation of the enzyme activity was recorded as a function of the irradiation time of the azo compound at the two reported wavelengths for three successive cycles. No decay in the enzyme response was observed during the cycles, indicating the reversibility of the process.