Friebolin H, Brossmer R, Keilich G, Ziegler D, Supp M
Hoppe Seylers Z Physiol Chem. 1980 May;361(5):697-702.
The 1H-NMR spectroscopy was used to study the anomeric configuration of N-acetyl-D-neuraminic acid released by the action of neuraminidase. The hydrolysis of NeuAcalpha 2 leads to 3 Gal-beta 1 leads to 4Glc (20mM) by the enzymes of Clostridium perfringens and Arthrobacter ureafaciens (50 mU, 150 mU and 800 mU, respectively) in 50mM Na/K-phosphate buffer pD 5.4 was observed by recording the spectra. On the basis of the characteristic signals of the protons at C-3 (alphaNeuAc: delta[H(3e)] = 2.72, delta[H(3a)] = 1.64; betaNeuAc: delta[H(3e)] = 2.25, delta[H(3a)] = 1.84) the product of the enzymatic cleavage was identified to be the N-acetylneuraminic acid in the alpha-anomeric form. Two hypotheses are discussed to explain how the enzymatic hydrolysis may occur and how N-acetyl-alpha-D-neuraminic acid leaves the catalytic site of the neuraminidases with retention of the C-2 configuration.
采用1H-NMR光谱法研究了神经氨酸酶作用释放的N-乙酰-D-神经氨酸的异头构型。通过记录光谱，观察到在50mM Na/K-磷酸盐缓冲液（pD 5.4）中，产气荚膜梭菌和脲节杆菌的酶（分别为50 mU、150 mU和800 mU）对NeuAcalpha 2导致3 Gal-beta 1导致4Glc（20mM）的水解作用。根据C-3位质子的特征信号（α-神经氨酸：δ[H(3e)] = 2.72，δ[H(3a)] = 1.64；β-神经氨酸：δ[H(3e)] = 2.25，δ[H(3a)] = 1.84），酶促裂解产物被鉴定为α-异头构型的N-乙酰神经氨酸。讨论了两种假说，以解释酶促水解可能如何发生以及N-乙酰-α-D-神经氨酸如何在保留C-2构型的情况下离开神经氨酸酶的催化位点。
