Human salivary amylase, a major component of human salivary secretions, possesses multiple functions in the oral cavity. It is the only enzyme in saliva capable of degrading oligosaccharides, which are used by the oral microflora for nutritional purposes. In order to understand its role in disease processes such as caries, we have undertaken the structure-function analyses of amylase. In this regard, the nonglycosylated human salivary amylase was expressed in a baculovirus expression system. The native and the recombinant amylases exhibit similar biochemical as well as biophysical properties. Unlike recombinant human pancreatic amylase, recombinant human salivary amylase is not glycosylated when expressed in a baculovirus system as determined from the crystal structure determination of the recombinant enzyme. Therefore, this system is suitable for further structure-function work without resorting to enzymatic removal of the carbohydrate chain. Details of the expression, purification, and biophysical properties will be presented. (C) 2002 Elsevier Science (USA).