¹H-NMR-Spektroskopischer Nachweis der N-Acetyl-α-D-neuraminsäure alsprimäresSpaltprodukt der Neuraminidasen

Abstract

Zusammenfassung: Die ^-NMR-Spektroskopie nen an C-3 (aNeuAc: 5[H(3e)] = 2.72, 6[H(3a)] = erweist sich als geeignete Methode, um die Kon-l.64; ]3NeuAc: 6[H(3e)] = 2.25, Ö[H(3a)] = 1.84) figuration des Spaltproduktes der Neuraminidasen findet man, daß die Neuraminidasen ./V-Acetylzu bestimmen. Der Verlauf der Hydrolyse von neuraminsäure in a.-anomerer Form aus dem Sub-NeuAca2 -» 3 GaljSl -»4Glc (20mM) durch die strat freisetzen. Neuraminidasen aus Clostridium perfringens und Arthrobacter ureafaciens (jeweils 50, 150 undZwei Vorstellungen zum Ablauf der enzymati-800 mU) in 50mM Na/K-Phosphatpuffer pD 5.4sehen Hydrolyse mit Abspaltung als W-Acetylwurde an Hand von l H-NMR-Spektren verfolgt.-D-neuraminsäure unter Erhalt der Konfigura-Mittels der charakteristischen Signale der Proto-tion an C-2 werden diskutiert.-NMR- Summary:The J H-NMR spectroscopy was used C-3 (oNeuAc: 6[H(3e)] = 2.72, 6[H(3a)] =1.64; to study the anomeric configuration of TV-acetyl-0NeuAc: 5[H(3e)] = 2.25, 5[H(3a)] = 1.84) the D-neuraminic acid released by the action of neu-product of the enzymatic cleavage was identified raminidase. The hydrolysis of NeuAca2 -» 3 Gal-to be the 7V-acetylneuraminic acid in the j31 -> 4Glc (20mM) by the enzymes of Clostri-a-anomeric form. dium perfringens and Arthrobacter ureafaciens Two hypotheses are discussed to explain how (50 mU, 150 mU and 800 mU, respectively) in the enzymatic hydrolysis may occur and how 50mM Na/K-phosphate buffer pD 5.4 was ob-N-acetyl-a-D-neuraminic acid leaves the catalytic served by recording the spectra. On the basis site of the neuraminidases with retention of the of the characteristic signals of the protons at C-2 configuration.

The structure of the complex between influenza virus neuraminidase and sialic acid, the viral receptor

“…This is the form in which the product is released from the active site of bacterial neuraminidases before the alp anomeric equilibrium in solution is established. 20 This "lysozyme-like" mechanism is not consistent with all the available data on the enzyme activity. Some data suggest a bell-shaped pH activity profile for the enzyme2'*22 with critical groups titrating at around pH 4.5 and 9.0.…”

Catalytic mechanism of enzymic glycosyl transfer

“…fringens and Arthrobacter ureafaciens enzymes work with retention of configuration 197. The gene coding for the sialidase of C. perfringens has been cloned and…”

Carbohydrates and carbohydrate degradation gene abundance and transcription in Atlantic waters of the Arctic

“…Most notable was the GH16_3 gene family, which contains enzymes that degrade laminarin [ 74 ], that constituted 3.1% of CAZyme gene abundance and 2.7% of CAZyme gene transcription. Other prominent gene families included those known to target sialic acids (GH33 [ 75 ]; ~1.4% of CAZyme abundance and 1.7% of CAZyme transcription), α-mannans (GH92 [ 76 ]; ~1.7% CAZyme abundance and ~1.3% CAZyme transcription) and alpha-linked fucose that is common in FCSPs [ 77 ] (GH29; ~1.3% CAZyme abundance and 1.2% CAZyme transcription) (Fig. 5 and Supplementary Tables S7 – S10 ).…”