BACKGROUND Low concentrations of pyridoxal-5'-phosphate (PLP), the active metabolite of vitamin B-6, are associated with high C-reactive protein (CRP) concentrations. Both low PLP and elevated inflammatory markers, such as high-sensitivity CRP (hs-CRP) and fibrinogen, are related to higher risk of coronary artery disease (CAD). OBJECTIVES The objectives were to evaluate the relation between P...

The central nervous system (CNS) of terrestrial vertebrates underwent a prominent molecular change when a tetraspan membrane protein, myelin proteolipid protein (PLP), replaced the type I integral membrane protein, P0, as the major protein of myelin. To investigate possible reasons for this molecular switch, we genetically engineered mice to express P0 instead of PLP in CNS myelin. In the absen...

Examination of brain myelin proteins by sodium dodecyl sulfate-gel electrophoresis followed by fluorography clearly showed that both proteolipid protein (PLP) and DM-20 were acylated 24 h after the intracerebral injection of 30-day-old rats with C3H]palmitic acid. The radioactivity associated with PLP remained after purification, re-electrophoresis, and fluorography. Most of the radioactivity a...

Previous studies have pointed towards a cofactor role for pyridoxal 5'-phosphate (PLP) in lysyl oxidase, the enzyme that generates the peptidyl aldehyde precursor to the lysine-derived cross-linkages in elastin and collagen. The nature of a carbonyl moiety in purified bovine aortic lysyl oxidase was explored in the present study. A PLP dinitrophenylhydrazone could not be isolated from lysyl oxi...

The myelin proteolipid protein (PLP) gene (i.e., the PLP/DM20 gene) has been of some interest because of its role in certain human demyelinating diseases, such as Pelizaeus-Merzbacher disease. A substantial amount of evidence, including neuronal pathology in knock-out and transgenic animals, suggests the gene also has functions unrelated to myelin structure, but the products of the gene respons...

Natural killer (NK) cells are the predominant lymphocytes present in healthy rodent and human implantation sites. In the rat, the expansion, differentiation and subsequent migration of NK cells away from the developing chorioallantoic placenta coincide with the expression of a novel pregnancy- and trophoblast cell-specific cytokine, prolactin (PRL)-like protein A (PLP-A). PLP-A specifically bin...

The formation of central nervous system myelin by oligodendrocytes requires sterol synthesis and is associated with a significant enrichment of cholesterol in the myelin membrane. However, it is unknown how oligodendrocytes concentrate cholesterol above the level found in nonmyelin membranes. Here, we demonstrate a critical role for proteolipids in cholesterol accumulation. Mice lacking the mos...

The proteolipid protein (Plp) gene promoter is responsible for driving expression of one of the major components of myelin--PLP and its splice variant DM-20. Both products are classically thought to express predominantly in oligodendrocytes. However, accumulating evidence suggests Plp expression is more widespread than previously thought. In an attempt to create a mouse model for inducing oligo...

In vitro supplementation with the active form of vitamin B6, pyridoxal-phosphate (PLP), increases measurements of both serum aminotransferase enzymes, L-aspartate: 2-oxoglutarate amino transferase, EC 2.6.1.1 (AST) and L-alanine: 2-oxoglutarate aminotransferase, EC 2.6.1.2 (ALT). The plasma PLP level in normal individuals clearly relates inversely to the degree of stimulation of serum AST and A...