Abstract

Isolation of Myosin from Mammalian Blood Platelets

Inhibiting amygdala actin polymerization disrupts methamphetamine-associated memories, which could potentially prevent relapse to substance use disorder (SUD), but because many cell processes rely on actin, inhibiting actin polymerization is not realistic as a therapeutic option for the prevention of SUD relapse. This research inhibits nonmuscle myosin II (NMII), a protein upstream of actin polymerization, for NMIIb triggers actin polymerization. In doing this, the result of inhibiting actin polymerization is achieved,— methamphetamine-associated memories are disrupted, as actin monomers do not form actin filaments in the neuronal cytoskeleton, not allowing dendritic spines to undergo necessary structural change during long-term memory formation—but because NMII has fewer bodily applications than actin, inhibiting NMII affects fewer bodily functions. Currently, blebbistatin, an inhibitor of myosin ATPase activity, has adverse properties, so blebbistatin derivatives would need to be developed and tested on blood platelet NMII as a therapeutic for SUD relapse. Typically, human blood platelets are used to isolate NMII, but they are more costly than other mammalian blood platelets, so it would be preferable if alternative platelets derived from non-human vertebrates could be used for NMII isolation and inhibition. In this research, pig, bovine, rabbit and human blood platelets are tested using ammonium sulfate precipitation to isolate NMII. Unlike bovine and pig blood platelets, rabbit blood platelets were successful in NMII isolation, potentially allowing for prevention of SUD relapse research to be more frequently conducted, as these platelets optimize NMII isolation, not only being less expensive but also more accessible than human blood platelets.