Mass spectroscopic characteristics of phosphoryl amino acids were studied in detail by positive and negative electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Be...Mass spectroscopic characteristics of phosphoryl amino acids were studied in detail by positive and negative electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Be- sides N-diisopropyloxyphosphoryl amino acids (N-DIPP-AA), O-phospho- and O-diisopropyloxyphosphoryl amino acids (O-DIPP-AA) were studied and compared to N-DIPP-AA. The fragmentation pathways of [M+H]+, [M+Na]+ and [M-H]- ions of phosphoryl amino acids were summarized. In addition to several similar patterns, each of them showed its characteristic fragmention.展开更多
The structure of dipepide AcMet-Gly was determined by X-ray crystallographic analysis. It possesses mono-clinic, space group P21 (No. 4), with cell dimensions of a=0.8571(2) nm, b=0.5871(2) nm, c=1.197(3) nm, =99.290(...The structure of dipepide AcMet-Gly was determined by X-ray crystallographic analysis. It possesses mono-clinic, space group P21 (No. 4), with cell dimensions of a=0.8571(2) nm, b=0.5871(2) nm, c=1.197(3) nm, =99.290(10), V=0.5944(15) nm3, Z=2, m=2.74 cm-1. Mononuclear chelates, described as [Pd(X)(S,N,O- AcMet-Gly)]+, in which Pd(II) is coordinated by thioether, deprotonated amide nitrogen, carbonyl oxygen of me-thionine and X (AcMetGly or other ligands present in aqueous solution or in mobile phase solution), were detected 5 min after mixing AcMet-Gly with [Pd(H2O)4]2+ at room temperature using electrospray ionization mass spectrometry. The geometry of [Pd(H2O)(S,N,O-AcMet-Gly)]+ is optimized at density functional B3LYP/LanL2DZ level. The fused five- and six-membered chelate is responsible for cleavage of Met-Gly bond. This is the first time to provide a direct evidence for Pd(II)-mediated cleavage of dipeptides via external solvent attack.展开更多
基金Project supported by the National Natural Science Foundation of China (No. 20175026).
文摘Mass spectroscopic characteristics of phosphoryl amino acids were studied in detail by positive and negative electrospray ionization mass spectrometry (ESI-MS) in conjunction with tandem mass spectrometry (MS/MS). Be- sides N-diisopropyloxyphosphoryl amino acids (N-DIPP-AA), O-phospho- and O-diisopropyloxyphosphoryl amino acids (O-DIPP-AA) were studied and compared to N-DIPP-AA. The fragmentation pathways of [M+H]+, [M+Na]+ and [M-H]- ions of phosphoryl amino acids were summarized. In addition to several similar patterns, each of them showed its characteristic fragmention.
基金Project supported by the National Natural Science Foundation of China (Nos. 20271027 20231010).
文摘The structure of dipepide AcMet-Gly was determined by X-ray crystallographic analysis. It possesses mono-clinic, space group P21 (No. 4), with cell dimensions of a=0.8571(2) nm, b=0.5871(2) nm, c=1.197(3) nm, =99.290(10), V=0.5944(15) nm3, Z=2, m=2.74 cm-1. Mononuclear chelates, described as [Pd(X)(S,N,O- AcMet-Gly)]+, in which Pd(II) is coordinated by thioether, deprotonated amide nitrogen, carbonyl oxygen of me-thionine and X (AcMetGly or other ligands present in aqueous solution or in mobile phase solution), were detected 5 min after mixing AcMet-Gly with [Pd(H2O)4]2+ at room temperature using electrospray ionization mass spectrometry. The geometry of [Pd(H2O)(S,N,O-AcMet-Gly)]+ is optimized at density functional B3LYP/LanL2DZ level. The fused five- and six-membered chelate is responsible for cleavage of Met-Gly bond. This is the first time to provide a direct evidence for Pd(II)-mediated cleavage of dipeptides via external solvent attack.