Assignment-Isomeric-Matching-r

To investigate the possibility of structural assignment based on negative-ion MS2 spectral matching, three isomeric pairs of 2-aminopyridine (PA)-derivatized non-fucosylated, fucosylated, and sialylated oligosaccharides (complex type N-glycans) were analyzed using high-performance liquid chromatographyion trap mass spectrometry (HPLCITMS) with a sonic-spray ionization (SSI) source. In the SSI negative-ion mode the deprotonated molecule [M-2H]2- becomes prominent. lacto-n-neotetraose -ion MS2 spectra derived from such ions contain many fragment types (B and Y, C and Z, A, and D) and therefore are more informative than the positive-ion MS2 spectra derived from [M+H+Na]2+ ions, which usually consist mainly of B and Y fragment ions. In particular the internal ions (D- and E-type ions) provided useful information about the alpha1-6 branching patterns and the bisecting GlcNAc residue. Spectral matching based on the correlation coefficients between negative-ion MS2 spectra was performed in a manner similar to the positive-ion MS2 spectral matching previously reported. It was demonstrated that negative-ion MS2 spectral matching is as useful and applicable to the structural assignment of relatively large non-fucosylated, fucosylated, and sialylated PA-oligosaccharide isomers as its positive-ion counterpart.

Roles of N-linked glycans in the endoplasmic reticulum.From a process involved in cell wall synthesis in archaea and some bacteria, N-linked glycosylation has evolved into the most common covalent protein modification in eukaryotic cells. The sugars are added to nascent proteins as a core oligosaccharide unit, which is then extensively modified by removal and addition of sugar residues in the endoplasmic reticulum (ER) and the Golgi complex. lacto n neotetraose has become evident that the modifications that take place in the ER reflect a spectrum of functions related to glycoprotein folding, quality control, sorting, degradation, and secretion. The glycans not only promote folding directly by stabilizing polypeptide structures but also indirectly by serving as recognition tags that allow glycoproteins to interact with a variety of lectins, glycosidases, and glycosyltranferases. Some of these (such as glucosidases I and II, calnexin, and calreticulin) have a central role in folding and retention, while others (such as alpha-mannosidases and EDEM) target unsalvageable glycoproteins for ER-associated degradation. Each residue in the core oligosaccharide and each step in the modification program have significance for the fate of newly synthesized glycoproteins.

DOI 146annurev.biochem311373752Growth performance and meat yields of broiler chickens fed diets containing low and ultra-low oligosaccharide soybean meals during a 6-week production period.Two experiments were conducted to determine the effects of diets containing low oligosaccharide soybean meals (SBM) on growth performance, meat yields, and physiological variables of broilers during a 6-wk production period. In experiment 1, six hundred Ross × Ross 8 male chicks were randomly distributed to 24 floor pens (25 birds per pen;9 m(2) per bird at 1 d of age). Birds were fed corn-soybean meal-poultry by-product meal-based diets with either low oligosaccharide (LOSBM) or control SBM (CSBM) from 1 to d of age. In experiment 2, one thousand five hundred Ross × Ross 8 male chicks were randomly distributed to floor pens (25 birds per pen;9 m(2) per bird at 1 d of age). Broilers were fed corn-soybean meal-poultry by-product meal-based diets containing 1 of 3 SBM sources [CSBM, LOSBM, or ultra-low oligosaccharide SBM (ULSBM)] and formulated with moderate or reduced AMEn concentrations (25 kcalkg reduction) resulting in a 3 × 2 factorial design.

Diets were formulated using AMEn and digestible amino acid values determined from previous research utilizing the same SBM types. Variables measured consisted of BW gain, feed intake, feed conversion ratio, mortality, carcass weight and yield, abdominal fat percentage, total breast meat weight and yield, digesta viscosities and pH, plasma nonesterfied fatty acids, plasma glucose, and plasma triglycerides. In experiment 1, broilers fed diets containing LOSBM had increased BW gain (P =) and decreased (P 01) feed conversion from 1 to 14 d of age. Abdominal fat percentage was higher (P 01) for birds fed LOSBM vs. CSBM. In experiment 2, no differences were observed for interaction effects or main effects of energy concentration. Feed conversion ratio was lower (P 01) for broilers fed diets containing ULSBM vs.

LOSBM and CSBM from 1 to 28 and 1 to 42 d of age. Broilers fed diets formulated with ULSBM had higher (P 5) carcass yield vs. birds fed diets with CSBM. Total breast yield was higher (P =21) for birds fed diets containing LOSBM and ULSBM vs. CSBM.