Biophysical analysis of electric current mediated nucleoprotein inactivation process

Motivation: Its well known the use of electric current in the cleaning of viral diseases in plants instead a deep knowledge of this phenomenas theoretical basis is not yet available. The description of the real causes of nucleoprotein inactivation, will contribute to the optimization of further experiments in order to obtain more and more efficient cleaning methodologies for starting material supplies of vegetal species micropropagation process. The dissipated energy as heat will depend on the specific treatment applied and on the physical properties of the vegetal tissue and viral nucleoprotein. Results: A hyperbolic dependence between the absorbance output values, obtained during a diagnostic micro-ELISA experiment, and the electrical power (in watts) applied to each explant was found. The former, demonstrate the cleaning process nature is essentially the effect over viral nucleoprotein denaturation, by means of the heat, to which they were exposed in the thermal bath that the vegetal tissue constitutes. Our results are consistent with mathematical developed from theoretical frame of harmonic oscillators in which molecular machine (viral nucleoproteins) could be redefined. Contact: E-mail: [email protected], [email protected] INTRODUCTION Electric current mediated cleaning of viral diseases in plants. Traditional techniques applied to cleaning of viral diseases in plants, i.e. Meristems culture, thermotherapy and chemotherapy fail to produce enough quantities of clean material in most species. Alternative procedures using electric current treatments have become in an efficient tool to overcome this problem. Black (1971) demonstrated a relation between growths stimulation in tomato plants that were treated with low current densities (3-15 μA/plants) during 4, 5, 12 and 24 hours and the ion concentrations detected. Blanchard (1974) applying 1 4 amperes DC pulsed to 6500 volt/hours, after 2 3 days, obtained clean tissues without microflora presence. Those results settled down the basis for the electrotherapy concept. Wagele (1978) patented his experience to use electrical current in obtaining grown bacterial cultures and tissues from various sources. Quacquerelli et al., (1980) applied electric current to Cactanucia tree stakes showing intense mosaic symptoms caused by virus, proving that treatments of 500 V/5-10 min. lead up to 90% of cleaned plants. Electrotherapy was then recommended in cleaning of Cucumber Mosaic Virus, Arabia Mosaic Virus, Grapevine Franleaf Virus, Chicory Yellow Motle and Tobaco Mosaic Virus. Based in these result, Hernández et al. (1997b) built a device to apply electric current in the cleaning of a viral complex in garlic (Allium sativum L.). They obtained an efficiency of 53-100% cleaned plant using 10-30 V treatments. Other applications of the same technology have been reported in sugar cane (Saccharum sp hybrid), potato (Solanum tuberosum) (Bernal, 1997), aroids (Xanthosoma sagitifolium) (Igarza et al. 2001) and banana plants (Musa ssp) (Hernández et al. 2002) for VMCA, PLRV, DMV and BSV respectively. Nevertheless, the lackness of homogeneity in the test (due to differences in explant electrical resistance) leads to differences of the electrical power that circulates through each of them, when fixed voltages or electrical currents are applied. Molecular machines. Harmonics molecular oscillators. Its known that molecular structures, proteic or nucleoproteic could be redefined as molecular machines. In other words, a molecular machine is just a simple macromolecule o a macromolecular complex. A molecular machine executes specific functions in living systems, they are isothermals. It means they are forced to work in a narrow range of temperatures in the thermal bath where they exist. Nevertheless, they can use the primary energy from surrounds to change its conformation into more flexible one. That is, essentially, a controlled way of denaturation what results in a loss of its biological function. Beyond the primary energy, any excess of energy is quickly dissipated leading the molecule confinement to the previous state at physiological temperature. A specific macromolecule receives a quantum of energy that put it from a basal state to an excited state. A further specific action always occurs dissipating the absorbed energy which is coupled to the realization of a specific function, evolutionarily advantageous for the organism who synthesized the macromolecule. Molecular machines could be stimulated by any energy source besides primary energy sources. That includes not only photons and ATP but also thermal movement like the restriction enzyme EcoRI isolated from its DNA binding site. EcoRI uses thermal fluctuations, originated by microscopical heat, as energy source to reach the DNA in a specific manner (Schneider, 1991a y 1991b). MATERIALS AND METHODS. Plants of the genotype Pacala Duclos (Dioscorea alata L.) serologically positives to potyviruses were used. Nodal segments (25 in total), treated with 15 volt DC for 5 minutes, were used as described by González 2005. Determination of the relation between Electrical Power and Absorbance Value of in the micro-ELISA test The electric current was measured in each of the explants. Then, the electrical power (energy vanished in form of heat) was calculated according to the equation: P = I x V. where: P is Electrical power (Joule/second) I is Current Intensity (Ampere) V is Voltage (watts) Theoretical modeling of the effect of the electrical power on viral nucleoproteins. The Molecular Machines inside the cells can be treated, or they behave, as harmonic oscillators in thermal bathroom. If the viral particles behave as oscillators, then we should hope the population's of viral particles half energy is proportional to the magnitude RT, where R is the gases constant y T is the absolute temperature, because RT is the media energy, for particle mole, for a oscillator in balance in a thermal bath (Schneider, 1991a y b). In particular, we assume that the viral particles behave as quantum oscillators, that is to say, they can take alone discreet securities of energy: εn = nxεo, where n is any integer and εo is the primary energy (joule/mole) of the particles in the thermal bath from which the virus begin to inactivate. Starting from this reasoning a theoretical model is developed to find the dependence between the Absorbance and the electrical power in each explant. Lineal regression of the experimental data. Fit to theoretical model. Using a transform dependent variable x=1/P, two linearization models were proved: a model with intercept y=bx+c+error, and a model without intercept y=bx+error (Darlington, 1990).