Structural consequences of the interaction of puroindolines with gluten proteins

Enoch T Quayson; Alessandra Marti; Craig F Morris; Mauro Marengo; Francesco Bonomi; Koushik Seetharaman; Stefania Iametti

doi:10.1016/j.foodchem.2018.01.146

Structural consequences of the interaction of puroindolines with gluten proteins

Food Chem. 2018 Jul 1:253:255-261. doi: 10.1016/j.foodchem.2018.01.146. Epub 2018 Jan 31.

Authors

Enoch T Quayson¹, Alessandra Marti², Craig F Morris³, Mauro Marengo⁴, Francesco Bonomi⁴, Koushik Seetharaman⁵, Stefania Iametti⁴

Affiliations

¹ Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108, USA; Department of Biochemistry, Science Building, University of Cape Coast, Cape Coast, Ghana.
² Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108, USA; Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via G. Celoria 2, 20133 Milan, Italy. Electronic address: alessandra.marti@unimi.it.
³ USDA-ARS Western Wheat Quality Laboratory, Washington State University, E-202 Food Science & Human Nutrition Facility East, Pullman, WA 99164, USA.
⁴ Department of Food, Environmental and Nutritional Sciences, Università degli Studi di Milano, via G. Celoria 2, 20133 Milan, Italy.
⁵ Department of Food Science and Nutrition, University of Minnesota, 1334 Eckles Ave., St. Paul, MN 55108, USA.

PMID: 29502829
DOI: 10.1016/j.foodchem.2018.01.146

Abstract

The effect of puroindolines (PINs) on structural characteristics of wheat proteins was investigated in Triticum turgidum ssp. durum (cv. Svevo) and Triticum aestivum (cv. Alpowa) and in their respective derivatives in which PIN genes were expressed (Soft Svevo) or the distal end of the short arm of chromosome 5D was deleted and PINs were not expressed (Hard Alpowa). The presence of PINs decreased the amount of cold-SDS extractable proteins and the accessibility of protein thiols to specific reagents, but resulted in facilitated solvation of gluten proteins, as detected by tryptophan fluorescence measurements carried out on minimally mixed flour/water mixtures. We propose that PINs and gluten proteins are interacting in the grain or flour prior to mixing. Hydrophobic interactions between PINs and some of the gluten proteins modify the pattern of interactions among gluten proteins, thus providing an additional mechanistic rationale for the effects of PINs on kernel hardness.

Keywords: 2-Mercaptoethanol (PubChem CID: 1567); 5,5′-Dithiobis-2-nitrobenzoic acid (PubChem CID: 6254); Acetonitrile (PubChem CID: 6342); Bromophenol Blue (PubChem CID: 8272); Coomassie blue R-250 (PubChem CID: 23693030); Dithiothreitol (PubChem CID: 446094); Gluten aggregation; Kernel texture; Protein thiols; Puroindoline proteins; Sodium dodecyl sulfate (PubChem CID: 3423265); Trifluoroacetic acid (PubChem CID: 6422); Tris (PubChem CID: 6503).

MeSH terms

Flour
Glutens / chemistry*
Glutens / metabolism*
Hardness
Hydrophobic and Hydrophilic Interactions
Indoles / chemistry*
Indoles / metabolism*
Protein Binding
Triticum / chemistry
Water / chemistry

Substances

Indoles
Water
indoline
Glutens