New experimental technique for detecting the effect of low-frequency electric fields on enzyme structure

✍ Scribed by Guido Greco Jr.; Liliana Gianfreda; Prof. Guglielmo d'Ambrosio Jr.; Rita Massa; Maria Rosaria Scarfi; Antonio Scaglione

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 719 KB
• Volume: 11
• Category: Article
• ISSN: 0197-8462
• DOI: 10.1002/bem.2250110108

✦ Synopsis

A new experimental approach has been developed to determine kinetic and thermodynamic parameters of the inactivation of an enzyme under labile conditions both with and without exposure to electrical currents as sources of perturbation. Studies were undertaken to investigate if low-frequency electric currents can accelerate the thermal inactivation of an enzyme through interactions with dipole moments in enzymatic molecules and through related mechanical stresses. The experiments were conducted with the enzyme acid posphatase. The enzyme was exposed to a 50-Hz current at different densities (10 to 60 mA/cm2 rms) or to a sinusoidal or square-wave current at an average density of 3 mA/cm2 and frequencies from, respectively, 50 Hz to 20 kHz and 500 pulses per second (pps) to 50.000 pps. Positive-control experiments were performed in the presence of a stabilizer or a deactivator. The results indicate that the technique is sensitive to conformational changes that otherwise may be impossible to detect. However. exposure to electric currents under the experimental conditions described herein showed no effects of the currents.