R-protein

R-pro·tein

(prō'tēn)
A protein produced by the salivary gland that is thought to protect vitamin B12 as it travels through the digestive tract.
References in periodicals archive ?
So far 20 members of the NOD family have been reported, such as apoptotic protease-activating factor-1 (APAF-1), nucleotide-binding oligomerization domain 1 (NOD1), NOD2, and disease-resistance proteins (R-protein), most representative of which is NOD1 and NOD2 [7-9].
Abbreviations APAF-1: Apoptotic protease-activating factor-1 BBB: Blood-brain barrier BWC: Brain water content CARD: Caspase-associated recruitment domain CSF: Cerebrospinal fluid EB: Evans blue GM-di: GlcNAc-MurNAc dipeptide [GM-Tri.sub.lys]: GlcNAc-MurNAc tripeptide muropeptide IHC: Immunohistochemistry IL: Interleukin IL-1[beta]: Interleukin-1 beta IL-6: Interleukin-6 MDP: Muramyldipeptide NOD1: Nucleotide-binding oligomerization domain 1 NOD2: Nucleotide-binding oligomerization domain 2 OD: Optical density PRR: Pattern-recognition receptors qRT- Quantitative real-time polymerase chain PCR: reaction R-protein: Disease-resistance proteins TNF: Tumor necrosis factor TNF-[alpha]: Tumor necrosis factor-alpha.
Although this procedure is not related to the denaturation process, it is common practice to minimize the effects of R-protein, and the IMMULITE 2000 vitamin [B.sub.12] assay incorporates cobinamide in its formulation for the same reasons.
These endogenous binding proteins include intrinsic factor (IF), transcobalamin-II (TC-II), and R-protein. IF exhibits almost no affinity for physiologically inactive forms of [B.sub.12] (including cobinamide), whereas TC-II and R-protein bind both physiologically inactive [B.sub.12] and physiologically active forms (e.g., cyanocobalamin).