Z Lebensm Unters Forsch. 1991 Mar;192(3):234-9.

Disulphide bonds in wheat gluten: isolation of a cystine peptide from glutenin.

Köhler P1, Belitz HD, Wieser H.

Gluten from the wheat variety Rektor was extracted with 70% aqueous ethanol. The residual protein (glutenin) was hydrolysed with trypsin. The partial hydrolysate was separated into seven fractions by gel permeation chromatography on Sephadex G 25. Four cystine-containing peptides were isolated from fraction 5 by reversed-phase high-performance liquid chromatography on ODS-Hypersil. The cystine peptides were detected by differential chromatography of the non-reduced and the reduced samples. The primary structure of the peptides was solved by the Edman degradation reaction and by partial hydrolysis with thermolysin. Three peptides derive from the alpha 2- and beta-purothionins. The structure of the fourth peptide was determined as (Formula; see text) This sequence corresponds to positions 44-48 of known sequences of the high molecular weight (HMW) subunits 9, 10, and 12. Since Rektor contains the HMW subunits 9 and 10, it could be concluded that two HMW subunits 9 or 10, or one subunit 9 and one subunit 10 were linked parallel via two disulphide bridges.

PMID:  2038894

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J Exp Med. 1942 Jan 31;75(2):179-89.

THE EFFECT OF VARIOUS DIETS ON THE LIVER DAMAGE CAUSED BY EXCESS CYSTINE.

Earle DP1, Victor J.

1. The effect of 9 different diets on the liver lesions resulting from excess dietary cystine has been studied in 130 rats.
2. The incidence and severity of each of the following liver lesions were varied by changes in the composition of diets containing 5 or 10 per cent cystine:
   (a) Hemorrhage was least severe with low fat diets.
   (b) Necrosis was most severe with synthetic diets.
   (c) Cirrhosis was delayed by a diet high in lard, 20 per cent, and cod liver oil, 5 per cent, but not by a diet high in butter, 25 per cent.
   (d) Fatty infiltration was found consistently only with low protein, high fat diets. In other words, the pathogenesis of the liver lesion due to excess dietary cystine can be modified by diet.
3. In the presence of cystine as 5 per cent of a low protein, high fat diet, 1 per cent choline inhibited fatty infiltration but did not protect the liver against damage by cystine.

4. In these experiments there was no apparent correlation between fatty infiltration of the liver and the incidence or degree of cirrhosis.

PMID:  19871175