N-linked

The rearranging entity has been shown to be the bivalent cation the adjacent charges may so weaken the N—N link that charges of nearly integral size may be built up in the 4 and 4 positions. In the bent, but strainless, cation the minimum separation of the two p-positions would suffice for the establishment of a lai ely electrostatic bond, which could pass smoothly into the covalent rearrangement product (benzidine). 

Fig. 2. Generalized structure of N-linked oligosaccharide of the pituitary glycoprotein hormones. SO = sulfate, GIcNAc = N — acetylglucosamine, GalNAc = N — acetylgalactosamine, Man = mannose, Fuc = fucose, SA = sialic (neuraminic) acid.

Fig. 3. Human CG, hLH, and equine CG (eCG) P-subunits. Amino acid numbeiing is relative to maximum homology between the three subunits. Consensus glycosylation sites ate at Asn-13 and 30. = same amino acid as hCG/3. Underlined Asn residues indicate attachment of N-linked carbohydrate chains. Serines at positions 121, 127, 132, and 138 of hCGP are underlined to indicate sites of O-linked carbohydrate attachment. Residues 115—118,...

N-Linked substituents O-Linked substituents S-Linked substituents C-Linked substituents Reactivity at the Ring Nitrogen Atoms Reduction Oxidation... 

N-Linked Substituents (Nitro and Amino Compounds and Azides)... 

Substituents Attached to Ring Nitrogen Atoms 4,02.3.12.1 N-Linked azole as a substituent... 

N,N -linked synthesis, 5, 269 6,6 -Biazulenes synthesis, 1, All Bibenzimidazolyls 3-oxides synthesis, 5, 412 1,1 - Bibenzimidazolyls synthesis, 5, 459 2,2 -Bibenzo[b]selenienyl synthesis, 4, 947 2,2 -Bibenzothiazolyl reduction, 6, 260 4,4 -Bichromenyl synthesis, 3, 743 Bicyclo[n. 1.0]alkanes retro-cycloaddition reactions, 1, 668 Bicyclo[5.3.0]decane synthesis, 1, 420 Bicyclo[4.1,0]diheteroheptanes synthesis, 3, 977... 

FIGURE 9.26 The carbohydrate tnoiedes of glycoproteins may be linked to the protein via (a) serine or threonine residues (in the O-linked saccharides) or (b) asparagine residues (in the N-linked saccharides), (c) N-Linked glycoproteins are of three types high mannose, complex, and hybrid, the latter of which combines structures found in the high mannose and complex saccharides. 

Many compounds containing the P-N link can be considered formally as derivatives of the oxoacids of phosphorus and their salts (pp. 510 -31) in which there has been isoclccironic replacement of ... 

Ketten-glied. n. link (or member) of a chain, -isomerie, /. chain isomerism, -kokken, m.pl. streptococci, -linie,/. catenary (curve), -moldktil, n. chain molecule, linear molecule, -polymer, n. chain polymer, linear polymer, -rad, n. sprocket wheel, -reaktion, /. chain reaction, -trieb, m. chain drive. 

Scheme 32 Diels-Alder reactions of C - N linked 2(lff)-pyrazinone-triazoles with DMAD...

These triazolo-pyrazinones were reacted with DMAD under microwave irradiation (Scheme 32). The reactions were carried out in o-DCB at a slightly elevated temperature of 200 °C for 15 min. Interestingly, the opposite selectivity to the C-C linked analogues was observed during the Diels-Alder reactions of C - N linked pyrazinone-triazoles with DMAD, as pyridines were found to prevail over the corresponding pyridinones. These compounds were isolated in combined yields of 39-68%. 

Fig. 2.47 The (P)-2.5-helical structure of N.N -linked oligoureas as determined by NMR meaurements in pyridine-c/5. (A) Stereo-view along the helix axis of a low energy conformer of nonamer 178 generated by restrained molecular dynamics calculations. (Adapted from [274]). The helix is characterized by (i) a rigid +)-SYnclinal arrangement around the C(a)-...

Galactose Hexose Gal UDP-Gal Often found subterminal to NeuAc in N-linked glycoproteins. Also found in core trisaccharide of proteoglycans. 

Glucose Hexose Glc UDP-GIc Present during the biosynthesis of N-linked glycoproteins but not usually present in mature glycoproteins. Present in some clotting factors. 

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