Could cyanogenic glycoside rich diet cause increased risk for carbamylation-induced protein damage in individuals with chronic inflammatory diseases?

Cyanogenic glycosides are found in a diverse group of plants and are metabolized into thiocyanate by the intestines and liver. Conversion of plant derived thiocyanates into cyanide and isocyanic acid occurs by the activity of neutrophil-derived enzyme myeloperoxidase. Therefore, increased intake of cyanogenic glycoside rich plant based diet may lead to increased isocyanic acid induced protein carbamylation in chronic inflammatory states (increased myeloperoxidase activity). As there is a close relationship between non-enzymatic post-translational modification and protein function, carbamylation induced structural changes also affect the functions of proteins. Carbamylation induced structural alterations of proteins have recently drawn a great attention in the current literature, especially regarding the alterations of proteins with long half-life such as type I collagen, elastin, α-crystallin. We hypothesize that a plant-based natural diet, rich in cyanogenic glycosides, may have unintended consequences on native protein structure/function in individuals with chronic inflammatory diseases such as chronic kidney and rheumatological diseases because of the higher rate of transformation of plant derived thiocyanates into isocyanic acid by the increased activity of neutrophil-derived enzyme myeloperoxidase. Regulation of myeloperoxidase activity or moderation of cyanogenic glycoside rich diet might be important in the prevention/modulation of dangerous protein carbamylation process, especially in this patient group.