Institute of Bioanalytical Chemistry, Center for Biotechnology and Biomedicine, Faculty of Chemistry and Mineralogy, Leipzig University, Deutscher Platz 5, 04103 Leipzig, Germany.
Rapid Commun Mass Spectrom. 2010 Mar 15;24(5):599-604. doi: 10.1002/rcm.4424.
Two cyclic theta-defensin peptides were isolated from leukocytes of the hamadryas baboon, Papio hamadryas, and purified to homogeneity by gel electrophoresis and reversed-phase high-performance liquid chromatography. Both peptides had high in vitro activity against Escherichia coli, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans. Here, we report their de novo sequencing by matrix-assisted laser desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS). This was accomplished by combining conventional enzymatic digestion with N-terminal derivatization by 2-sulfobenzoic acid cyclic anhydride (SACA) or 4-sulfophenylisothiocyanate (SPITC) to facilitate the interpretation of fragment ion spectra. In addition to the two cyclic theta-defensins (PhTDs) we also sequenced a novel Papio hamadryas alpha-defensin, PhD-4, which showed high sequence homology to rhesus alpha-defensin RMAD-1 and human alpha-defensin HNP-1.
从绢毛猴（Papio hamadryas）白细胞中分离到两种环θ防御素肽，并通过凝胶电泳和反相高效液相色谱法纯化为均相。两种肽对大肠杆菌、单核细胞增生李斯特菌、耐甲氧西林金黄色葡萄球菌（MRSA）和白色念珠菌均具有高体外活性。在这里，我们通过基质辅助激光解吸/电离串联飞行时间质谱（MALDI-TOF/TOF-MS）报告了它们的从头测序。这是通过结合常规酶解和 N 端通过 2-磺基苯甲酸环酐（SACA）或 4-磺苯基异硫氰酸酯（SPITC）衍生化来完成的，以促进片段离子光谱的解释。除了两种环θ防御素（PhTDs）外，我们还对一种新型的绢毛猴α防御素 PhD-4 进行了测序，它与恒河猴α防御素 RMAD-1 和人α防御素 HNP-1 具有高度序列同源性。
