Differential scanning calorimetry of albumin solders: Interspecies differences and fatty acid binding effects on protein denaturation

Background and Objective: Understanding albumin solder denaturation is impo rtant for laser tissue soldering. Human (HSA), bovine (BSA), porcine (PSA), and canine (CSA) albumin both fatty acid containing (FAC) and fatty acid f ree (FAF) were evaluated by using differential scanning calorimetry (DSC). Study Design/Materials and Methods: DSC was used to measure difference ther mograms to determine the irreversible thermal denaturation profile for 50% albumin solutions. The denaturation transition's onset, end and peak temper atures, and enthalpy were measured. Results: All FAC species, except BSA, exhibited twin peaked endotherms. Sin gle endotherms were observed for all FAF species and BSA-FAC. Onset and end temperatures were significantly [P < 0.001] lower for all FAF species (exc ept BSA's end temperature). There was a 30% decrease in the denaturation en thalpy between FAF and FAC groups. Conclusion: FAF albumin solders were found to denature at significantly low er temperatures, while also having a 30% reduction in enthalpy when compare d with their FAC counterparts. Lasers Surg. Med. 27:465-470, 2000. (C) 2000 Wiley-Liss, Inc.