CO2 carbamylation of proteins as a mechanism in physiology

Abstract

Carbamate bonds occur following the nucleophilic attack of CO2 on to an amine. In proteins, this can occur at lysine side chains or at the N-terminus. For CO2 binding to occur an amine must be present in the NH2 form and consequently carbamates represent a site-specific post-translational modification, occurring only in environments of reduced hydration. Due to the specific nature of these interactions, coupled with the inability of these bonds to survive protein preparation methods, carbamate reactions appear rare. However, more biologically important examples continue to emerge that use carbamates as key parts of their mechanisms. In this review, we discuss specific examples of carbamate bond formation and their biological consequences with an aim to highlight this important, and often forgotten, biochemical group.

Uncovering sperm metabolome to discover biomarkers for bull fertility

“…However, it is new the description of carbamate in bull spermatozoa as well as its higher abundance in sperm from HF bulls. Endogenous carbamate is generated by the interaction of cellular carbon dioxide (CO 2 ) with an NH 2 group of primary and secondary amines [60, 61] when the concentration of CO 2 increases [62]. The formation of carbamate influences the function of hemoglobin as well [63].…”

Omega-3 fatty acids correlate with gut microbiome diversity and production of N-carbamylglutamate in middle aged and elderly women

“…In addition, we report that DHA serum levels correlate with the faecal concentration of NCG after adjusting for multiple testing. This carbamylated aminoacid, is available as a synthetic compound, but may also be generated in nature by protein carbamylation 57 . Given that the other faecal compounds strongly associated with DHA serum levels are omega-3 faecal levels and a dipeptide considered as a marker of animal protein (such as fish) intake, the abundance of this compound in the faeces is unlikely to be the result of intake of a supplement containing it.…”

Opposing modulation of Cx26 gap junctions and hemichannels by CO2

“…This reaction differs from carbamylation involving cyanate, which results in a very stable modification of the amine. Unlike this latter reaction, CO 2 carbamylation is a highly reversible post‐translational modification (Lorimer, 1983; Meigh, 2015).…”