This chemical modification provides a novel class of materials named carboxylated agarose. Protein S binds to negatively charged phospholipids via the carboxylated Gla domain. Biotin is initially carboxylated at the BC active site by ATP and bicarbonate. Bicinchoninic acid is a weak acid composed of two carboxylated quinoline rings. The fraction of carboxylated adamantane was 55-60%. The propionyl-CoA is first carboxylated to ("S")-methylmalonyl-CoA by the enzyme Propionyl-CoA carboxylase. An improved version of nitrile butadiene rubber (NBR) is carboxylated nitrile butadiene rubber (XNBR).