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Abstract
IgA protease, a proteolytic enzyme found in human saliva and colonic fluid, hydrolyzes human serum IgA immunoglobulins to yield Fabα and Fcα fragments. The enzyme is produced by organisms in the normal human microflora and can be purified from culture filtrates of the common human oral organism Streptococcus sanguis (American Type Culture Collection no. 10556). IgA protease is inactive against all other protein substrates examined including the other classes of human immunoglobulins. The role of this enzyme in affecting the function of the secretory IgA immune system is unknown.
Authors
Andrew G. Plaut, Richard Wistar Jr., J. Donald Capra
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