Some thermodynamic parameters of pancreatic and salivary alpha-amylase in serum.

Using monoclonal antibodies and 4,6-ethylidene-protected 4-nitrophenylmaltoheptaoside as substrate we determined the Arrhenius slope, the apparent energy of activation and the apparent enthalpy changes of total amylase, pancreatic amylase and salivary amylase in serum. The Arrhenius slope and hence the other thermodynamic parameters of pancreatic amylase are significantly different from those of total amylase or salivary amylase, but identical to those obtained for purified human pancreatic amylase. Similarly, the thermodynamic parameters of serum salivary amylase activity are the same as those of the purified enzyme. Temperature conversion factors are given for amylase and its isoenzymes. The results are discussed briefly.