Synthese von Verbindungen des Pektins mit Eiweißstoffen (Antigene und Krebs, VII. Mitteilung)

Publisher Website
Google Scholar
Abstract
These expts. were undertaken to determine what residue must be introduced into a nonantigenic protein in order to give it antigenic properties. The methyl ester of pectin was prepd. by boiling pectin with methanol containing 3% HC1 for 6-7 hrs. Pectin hydrazide was prepd. by incubating 185 g. of the pectin ester and 1.5 g. hydrazine hydrate in 250 ml. methanol 2-3 days at 38[degree]. The ester pectin hydrazide was dissolved in 2% HCl soln., treated with an excess of 30% NaNO2 soln., and pectin azide precipitated by dioxane. Pectin gelatin was obtained by adding aqueous gelatin soln. to the pectin azide soln., keeping the reaction mixture alk. with N/10 NaOH for 20 min., and then precipitating the pectin gelatin with N/10 acetic acid. Pectin globulin was prepd. from horse serum pseudoglobulin in a similar way. The above procedures were also used in obtaining pectin-N-tyrosyl-ethyl ester, pectin-N-tyrosyl-hydrazide, pectin-tyrosyl-gelatin, pectin-tyrosyl-globulin, pectin-N-d-glucosamic acid ethyl ester and pectin-d-glucosamic acid hydrazide. To det. the antigenic properties, 20-50 mg. of the compounds dissolved in 2-5 ml. 1% NaHCO3 soln. were injd. intraven. into 2- to 3-kg. rabbits 3 times a week. The tyrosyl compounds were quite toxic, and sometimes caused great loss of wt., blindness, and death. The precipitin reaction in the blood of the rabbits was detd. by turbidity measurements in the Zeiss-Pulfrich photometer. Pectin coupled to gelatin is not an antigen, but the introduction of the tyrosine residue makes pectin-tyrosyl-gelatin an antigen. In this connection, glucosamic acid cannot replace the tyrosine residue and pectin glu- cosamic acid gelatin is not an antigen. However, one cannot conclude that these conditions determine the anti-genic or nonantigenic character of a protein. Further expts. were prevented by bombings.

This publication has 0 references indexed in Scilit: