A spectrophotometric study of blood group A-specific substance isolated from hog gastric mucosa

Abstract

A study of the ultraviolet absorption spectra of preparations of blood group A-specific substance isolated from hog gastric mucin supports the view that group A substance, and probably group O substance, has little specific absorption in this spectral region and that other components account for most if not all of the specific absorption noted in the case of impure preparations. However, ultraviolet spectrophotometric analyses have been found to be particularly useful in following changes in composition brought about by the fractionation of group A substance preparations obtained from hog gastric mucin as well as in comparing preparations isolated by different methods and from different sources. Such analyses have also indicated that tyrosine and tryptophan, if indeed present in group A substance, are but minor constituents.