Lactoperoxidase-Catalyzed Oxidation of Thiocyanate by Hydrogen Peroxide: A Reinvestigation of Hypothiocyanite by Nuclear Magnetic Resonance and Optical Spectroscopy
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- 作者：Pé ; ter Nagy ; Susan S. Alguindigue ; Michael T. Ashby
- 刊名：Biochemistry
- 出版年：2006
- 出版时间：October 17, 2006
- 年：2006
- 卷：45
- 期：41
- 页码：12610 - 12616
- 全文大小：79K
- 年卷期：v.45,no.41(October 17, 2006)
- ISSN：1520-4995
文摘
In an effort to reconcile conflicting reports regarding the spectra of the human defense factorhypothiocyanite (OSCN-), we have synthesized OSCN- by three methods and characterized the productspectroscopically. Method I is lactoperoxidase-catalyzed oxidation of SCN- by H2O2 at pH 7. Method IIis hydrolysis of (SCN)2 at pH 13. Method III is oxidation of SCN- by OX- (X = Cl and Br) at pH 13.All three methods produced essentially the same initial UV, 13C NMR, and 15N NMR spectra. The UVspectrum reveals a 
max of 376 nm, which is a previously unreported distinguishing feature. The 13CNMR spectrum (
= 127.8 ppm at pH 13 vs dioxane at 66.6 ppm) is comparable to those that have beenpreviously reported for OSCN- as prepared by methods I and II (although in some cases differentassignments have been made). However, the 15N NMR spectrum we measure ( = -80.6 ppm at pH 13vs NO3- at 0 ppm) contrasts with previous reports. We conclude that all three methods produce the samespecies, and the spectra are now self-consistent with the formulation OSCN-.
max of 376 nm, which is a previously unreported distinguishing feature. The 13CNMR spectrum ( = 127.8 ppm at pH 13 vs dioxane at 66.6 ppm) is comparable to those that have beenpreviously reported for OSCN- as prepared by methods I and II (although in some cases differentassignments have been made). However, the 15N NMR spectrum we measure ( = -80.6 ppm at pH 13vs NO3- at 0 ppm) contrasts with previous reports. We conclude that all three methods produce the samespecies, and the spectra are now self-consistent with the formulation OSCN-.