BACKGROUND Carbamylation is a posttranslational modification of proteins resulting from the nonenzymatic reaction between isocyanic acid and specific free functional groups. This reaction alters protein structural and functional properties and thus contributes to molecular ageing. Many studies have shown the involvement of carbamylated proteins in diseases, especially in chronic renal failure a...

In eight patients with sickle cell anemia, weekly extracorporeal carbamylation of about 20% of the circulating red cell mass was carried out for 2 yr or longer. At each visit, a mean of 1.3+/-0.2 mol of cyanate were incorporated per mole of hemoglobin in the carbamylated erythrocytes. Within 3 mo, a stable level of about 35-50% of the circulating erythrocytes was carbamylated. This quantity and...

Activity ratios and carbamylation ratios of ribulose-1,5-bisphosphate carboxylase (RuBPCase) were determined for leaves of Phaseolus vulgaris and Spinacia oleracea exposed to a variety of partial pressures of CO(2) and O(2) and photon flux densities (PFD). It was found that activity ratios accurately predicted carbamylation ratios except in extracts from leaves held in low PFD. In particular, i...

Cyanate is undergoing study as a drug to prevent occlusive sickle cell crises. Carbamylation of hemoglobin S increases its oxygen affinity, thereby decreasing its tendency to aggregate at low oxygen tensions. The cell membrane has also been shown to be carbamylated. We studied the effect of carbamylation on deformability of sickle, normal, and stored normal erythrocytes. Deformability was measu...

BACKGROUND AND OBJECTIVES The mechanisms underlying erythropoietin resistance are not fully understood. Carbamylation is a post-translational protein modification that can alter the function of proteins, such as erythropoietin. The hypothesis of this study is that carbamylation burden is independently associated with erythropoietin resistance. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In ...

Carbamylation describes a nonenzymatic posttranslational protein modification mediated by cyanate, a dissociation product of urea. When kidney function declines and urea accumulates, the burden of carbamylation naturally increases. Free amino acids may protect proteins from carbamylation, and protein carbamylation has been shown to increase in uremic patients with amino acid deficiencies. Carba...

In chronic kidney disease (CKD), metabolic derangements resulting from the interplay between decreasing renal excretory capacity and impaired gut function contribute to accelerating progression enhancing risk of complications. To protect residual improve quality life in conservatively managed predialysis CKD patients, current guidelines recommend protein-restricted diets supplemented with essen...

the non-enzymatic carbamylation of low density lipoprotein (ldl) is a naturally occurring chemical modification of apolipoprotein b as a result of condensation between lysine residues and cyanate derived from urea. carbamylated ldl is poorly recognized by ldl receptors and initiates different processes that can be considered proatherogenic. thus, ldl carbamylation may contribute to the increase...

Protein carbamylation is a post-translational modification that can occur in the presence of urea. In solution, urea is in equilibrium with ammonium cyanate, and carbamylation occurs when cyanate ions react with the amino groups of lysines, arginines, protein N-termini, as well as sulfhydryl groups of cysteines. The concentration of urea is elevated in the renal inner medulla compared with othe...

The non-enzymatic carbamylation of low density lipoprotein (LDL) is a naturally occurring chemical modification of apolipoprotein B as a result of condensation between lysine residues and cyanate derived from urea. Carbamylated LDL is poorly recognized by LDL receptors and initiates different processes that can be considered proatherogenic. Thus, LDL carbamylation may contribute to the increase...