ATPASE AND ATPSYNTHETASE ACTIVITY IN MYOSIN EXPOSED TO LOW-POWER LASER AND PULSED ELECTROMAGNETIC-FIELDS

Myosin can interact with actin in the presence of ATP and Ca2+. The resulting association gives rise to an actomyosinic complex which is involved in muscle contraction. Purified myosin contains the enzyme ATPase which catalyses the breakdown of ATP (in ADP plus inorganic phosphate (Pi)). This fundamental enzymatic mechanism is involved in transducing chemical into kinetic energy through the actomyosinic complex. The myosin ATPase activity can be inactivated by chemical (3 M urea, CO2) or physical agents (thermal shocks). Partial recovery of the inhibited activity has been obtained by exposure to low power laser radiation (GaAs and He-Ne) or weak magnetic pulsed fields. The myosin ATPase reverse reaction (ATP synthesis) occurs by incubating myosin ATPase in the presence of ADP (excess), Pi and a system for H+ production (lactate dehydrogenase, lactate, NAD+). Again the enzYmatic activity is increased by exposure to low power laser fields or weak magnetic pulsed fields.