The Composition and some Structural Features of the Principal Gastric Glycoprotein

Abstract

Gel chromatography on Sephadex G150 or Bio-gel P150 resolved the gastric secretions into three fractions. The non-retarded fraction contained 70–90% of the total carbohydrate eluted in the three fractions. The gastric secretions before gel filtration and the non-retarded fraction contained the same carbohydrate residues and the three carbohydrate components, galactose, glucosamine and galactosamine, in the same quantitative proportions. The amino-acid composition of the non-retarded fraction showed marked similarities and characteristic quantitative relationships. Threonine and serine were found to constitute 45–50% of the total aminoacid content. The analytical data, ultracentrifugation and light scattering studies suggest that the non-retarded fraction is composed of macromolecules which have a common basic composition but which are polydisperse with reference to their charged end groups, fucose and size.

Mucinous Secretion of Totally Isolated Porcine Stomach Perfused with Homologous Blood

“…It may be noted that the two 'treatment groups', histamine (H) and pentagastrin (P), did not differ statistically. The order of amino acids enumerated in this table is the same as in Schrager's [18] study, but we included two more amino acids, methionine and half-cystine, which were omitted by Schrager. Total amino acid content was 33.87 niM/1 in the histamine group and 34.37 mM/1 in the pentagastrin group.…”

“…This was done previously by other investigators [1,[17][18][19][20][21][22], Nor will we try to compare our results with those obtained in in vivo con ditions by different methods and in different species [1-3, 15, 25-27], In our discussion we will essentially refer to the studies of Schrager and Oates, which inspired our work and which supplied us with the metho dology.…”

“…In the discussion on quantitative analysis of carbohydrate components in human gastric secretion, Schrager [18] and Schrager and Oates [20][21][22], suggested, for the first time, some constant relationships be tween certain sugars. Galactose and glucosamine were found in equimolar amounts.…”

“…The techniques employed here for analysis of components of gastric mucus were those described by Schrager |18, 19| and Schrager and Oates [17,[20][21][22], We determined carbohydrate components D-galactose, D-mannose, L-fucose, D-glucosamine and D-galactosaniine [17,[19][20][21][22], We also analyz.ed these samples for total sulfate and total sugars [18,21] and for amino acids.…”

“…Total sulfate was determined with the barium method and color, developed with Sulphonize III solution, was read at 642 nm. Total sugars were measured using the Orcinol method (18,21]. Amino acids were determined using a Beckman 121-amino acid dialyzer (Beckman Instruments, USA).…”