All 46 enzymes were also subjected to a protein thermal shift assay spanning a range of 20°C to 99°C to determine melting temperatures (Figure and Table ). A resistance to unfolding at high temperatures is a valuable characteristic when used in many industrial applications, so determining which laccases are highly stable will inform target selection for engineering. The average melting temperatures of Group A and E were shown to be 60.9°C and 56.0°C respectively. An almost 5°C advantage to group A is surprising, as it is comprised of laccases with the trimeric motif while E represents monomeric laccases. We interpret this to mean that either the hydrogen bonding of the interfaces between the trimeric structures is strong enough to resist high temperatures or that they are indeed separating and there are insufficient hydrophobic amino acids that are exposed to generate a signal for the dye-based qPCR assay utilized. Another important observation is that laccases that came from thermophilic organisms like Pyrobaculum aerophilum (Q8ZWA8) and Thermus thermophilus (Q72HW2) were only about 2°C higher than the average melting temperature, while the laccase from Marinobacter guineae (A0A2G1VLD0), an organism collected in the Antarctic region, showed a melting temperature 25°C higher than average. This supports the importance of broadly surveying natural space for proteins of interest.