Zhong-Zhou Chen

Tsinghua University, Peping, Beijing, China

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Publications (12)19.78 Total impact

  • Zhong-Zhou Chen · Yan-Mei Li · Hai-Yan Wang · Jin-Tang Du · Yu-Fen Zhao
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    ABSTRACT: The beta-OH group is more active than gamma-OH in many processes, such as the catalysis of the active site in enzymes and the N-->O rearrangement of N-phosphoryl amino acids in negative-ion electrospray ionization mass spectrometry. The pentacoordinate phosphoric intermediates are proposed and the rearrangement mechanisms are studied by ab initio and density functional calculations. The formation of the intermediates comprises a concerted route and two different stepwise pathways. The concerted route is more favored. The cleavage of the P-N bond is the rate-determining step and is favored by the proton transfer. For the rearrangement of dimethoxyl phosphoryl serine anion and homoserine anion, the activation energies are 91.2 and 156.9 kJ/mol at the B3LYP/6-31+G(d,p) level, respectively. Therefore, the beta-OH group is predicted to be more active than gamma-OH and the result is in good agreement with the experiments.
    No preview · Article · Sep 2004 · The Journal of Physical Chemistry A
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    ABSTRACT: N-phosphoryl amino acids (PAA) are a unique chemical species with many chemical reactivities and properties, including the ability to self-assemble into oligopeptides. Because of their chemical characteristics, they have been proposed as the common origin for both nucleic acids and proteins. In this paper, we discussed six intramolecular mixed carboxylic–phosphoric anhydrides (IMCPAs) as possible intermediates for the prebiotic synthesis of biopolymers from PAA. We also investigated the role of water molecules in the formation of IMCPA using density functional theory B3LYP quantum mechanical calculations at the 6-31G** and 6-311+G** levels. Our results showed that the energy barrier of IMCPA formation was reduced from 19.5 kcal mol−1 to 9.9 kcal mol−1 when water participation and solvent effects were considered. Thus, the direct participation of one water molecule and the bulk solvent effects both play important roles in the formation of IMCPA.
    Full-text · Article · Mar 2004 · Journal of Molecular Structure THEOCHEM
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    ABSTRACT: In recent years β-amino acids have increased their importance enormously in defining secondary structures of β-peptides. Interest in β-amino acids raises the question: Why and how did nature choose -amino acids for the central role in life? In this article we present experimental results of MS and 31P NMR methods on the chemical behavior of N-phosphorylated -alanine, β-alanine, and -amino butyric acid in different solvents. N-Phosphoryl -alanine can self-assemble to N-phosphopeptides either in water or in organic solvents, while no assembly was observed for β- or -amino acids. An intramolecular carboxylic–phosphoric mixed anhydride (IMCPA) is the key structure responsible for their chemical behaviors. Relative energies and solvent effects of three isomers of IMCPA derived from -alanine (2a–c), with five-membered ring, and five isomers of IMCPA derived from β-alanine (4a–e), with six-membered ring, were calculated with density functional theory at the B3LYP/6-31G** level. The lower relative energy (3.2 kcal/mol in water) of 2b and lower energy barrier for its formation (16.7 kcal/mol in water) are responsible for the peptide formation from N-phosphoryl -alanine. Both experimental and theoretical studies indicate that the structural difference among -, β-, and -amino acids can be recognized by formation of IMCPA after N-phosphorylation. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 232–241, 2003
    No preview · Article · Sep 2003 · International Journal of Quantum Chemistry
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    ABSTRACT: Pentacoordinated phosphoranes containing valine or iso-leucine residue (2-phenyl-2,7-spiro[1,3,2-phenanthrodioxaphosphole-2,2′-1,3,2-oxazaphospholan]-5′-one) were synthesized through sequential two-step reactions, whereby the reaction products of phenyldichlorophosphine with N,O-bis(trimethylsilyl)valine or iso-leucine were followed by the addition of phenanthrenequione, and the crystals of 4a and 4b were obtained from benzene and hexane mixed solution. The x-ray structure of the crystals 4a and 4b revealed that they are distorted TBP, exhibiting RP absolute configuration. The P NMR spectra showed that the SP diastereomer could transfer into the other one RP that came out from the solution during crystallization. Correspondingly, when it was dissolved in solvents the RP diastereomer transferred into the other one SP, and the pair of diastereomers changed each other in solution at room temperature through a phosphonium carboxylate zwitterions intermediate.The work was supported by the National Natural Science Foundation of China (No. 29902003), the National Science and Technology Committee of China, the Chinese Education Ministry, and Tsinghua University.
    No preview · Article · Sep 2003 · Phosphorus Sulfur and Silicon and the Related Elements
  • Zhong-Zhou Chen · Bo Tan · Yan-Mei Li · Yu-Fen Zhao · Yu-Feng Tong · Jin-Feng Wang
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    ABSTRACT: N-phosphorylamino acids are chemically active species that have many biomimic activities. alpha-COOH in amino acids and peptides behaviors rather differently than beta-COOH in many biochemical processes and takes a more important role in the origin of life. Activity differences between alpha-COOH and beta-COOH in the peptide formation of phosphoryl amino acids are studied by 1D, 2D NMR techniques and by ab initio and density functional theory (DFT) calculations in this paper. Phosphoryl dipeptide is formed directly from phosphoryl aspartic acids without any coupling reagents. Only the alpha-dipeptide ester is observed by 1D (1)H, (13)C, and (31)P NMR and 2D NMR. In the ab initio and DFT calculations, the pentacoordinate phosphorane intermediates containing five-membered rings are predicted to be more favored than those with six-membered rings. Both the experimental results and the theoretical calculations suggest that only the alpha-COOH group is activated by N-phosphorylation in N-phosphorylaspartic acid under mild conditions.
    No preview · Article · Jun 2003 · The Journal of Organic Chemistry
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    ABSTRACT: The symmetry phosphoramidite reagents were synthesized via a two-step route and used for the ‘one pot’ synthesis of the phosphoserine building block Fmoc-Ser(PO(OBzl)OH)-OH. The procedure is simple and rapid, and product is obtained in high yield. When using this building block, the phosphopeptide (RKGS(PO3H2)SSNEPSSDSLSSPTLLAL) related to the C-terminal of c-Fos protein was synthesized manually by Fmoc/t-Bu procedure and characterized by matrix assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometry. In the fragment ion of phosphopeptide in the MALDI-TOF mass spectrometry with a curved field reflection, the acquired information can be used to identify the sequences and the phosphorylation sites of the peptide.
    No preview · Article · Jan 2003 · Letters in Peptide Science
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    Zhong-Zhou Chen · Yan-Mei Li · Yu-Fen Zhao
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    ABSTRACT: Newlase F, a crude enzyme containing lipase and protease, can be used in the synthesis of peptide conjugates; the hydrolysis conditions were optimized to increase lipase activity and suppress protease activity and in addition, N-terminal protecting groups and peptide bonds were not affected.
    Preview · Article · Dec 2002 · Journal of Chemical Research (Miniprint)
  • Zhong-Zhou Chen · Yan-Mei Li · Jing Ma · Bo Tan · Satoshi Inagaki · Yu-Fen Zhao
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    ABSTRACT: The biomimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes, such as origin of proteins and phosphorylation of amino acid residues in the proteins. The differences in reactivities between α-COOH and γ-COOH in phosphoryl amino acids were studied by ab initio and density functional methods. The pentacoordinate phosphoric intermediates 2 containing five-membered rings were predicted to be more stable than 3 with seven-membered rings. For intermediates 3, the isomers with apical-equatorial ring spanning arrangement were predicted to be more stable than those with diequatorial ring spanning arrangement. At the B3LYP/6-31G** level, intermediates 2 were 66.56 kJ/mol lower in energy than 3. It was shown that the transition states 4 and 5 involving an α-COOH or γ-COOH group had energy barriers of ΔE = 57.59 kJ mol-1 and 120.93 kJ mol-1, respectively. The theoretical calculations suggested that the α-COOH group could be differentiated from the γ-COOH intramolecularly in amino acids by N-phosphorylation. These might be helpful to understand why only α-COOH, not γ-COOH, was involved in the biomimic reactions.
    No preview · Article · Oct 2002 · The Journal of Physical Chemistry A
  • Zhong-Zhou Chen · Yan-Mei Li · Xi Peng · Fu-Rong Huang · Yu-Fen Zhao
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    ABSTRACT: A crude lipase, Newlase F, was used to remove C-terminal protecting groups from dipeptide esters. Hydrolysis of dipeptide n-heptyl esters with Newlase F was conducted in aqueous media containing acetonitrile. The optimum pH and temperature of lipase in Newlase F were 7.0 and 30°C, respectively. Low level acetonitrile promoted the hydrolysis of dipeptide n-heptyl esters, while high level acetonitrile inhibited the hydrolysis. However, the protease activity in Newlase F was significantly inhibited by acetonitrile. Lipase in Newlase F worked better in a medium containing water-miscible organic solvents than in water-immiscible ones. N-terminal protecting groups were not affected by the protease in the crude enzyme. It was found that the protease in Newlase F did not hydrolyze amide bond with hydrophilic amino acids on either side under these conditions (pH 7.0, room temperature). Newlase F may consequently be used widely in the synthesis of peptide conjugates. The crude enzyme was immobilized on SBA-15 mesoporous molecular sieve. The lipase activity of immobilized preparation was more active on hydrolysis of C-terminal protecting groups and stable than the free enzyme. The immobilization also reduced the protease activity.
    No preview · Article · Oct 2002 · Journal of Molecular Catalysis B Enzymatic
  • Zhong-Zhou Chen · Bo Tan · Yan-Mei Li · Yu-Fen Zhao

    No preview · Article · Aug 2002 · Phosphorus Sulfur and Silicon and the Related Elements
  • Zhong-Zhou Chen · Shui-Bing Chen · Yi Chen · Yan-Mei Li · Jing Chen · Yu-Fen Zhao
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    ABSTRACT: The negative-ions of N-phosphoryl amino acids were studied by electrospray ionization tandem mass spectrometry (ESI-MS/MS). The negative-ion ESI-MS/MS of N-phosphoryl amino acids showed characteristic fragmentation patterns different from those observed in the corresponding positive-ion ESI-MS/MS and negative-ion fast-atom bombardment mass spectra. For negative-ion ESI-MS/MS, a unique fragmentation from the N-terminal of N-phosphoryl amino acids or peptides containing a free beta-OH or CO(2)H group was observed to yield the characteristic fragment ion (RO)(2)P(O)O(-). The ease of the rearrangement depended on the position of the hydroxyl group in amino acids or peptides, and the N --> O rearrangement mechanism was proposed to involve the participation of the hydroxyl group. From previous solution-phase experiments and theoretical calculations, it was found that the beta-OH group was more active than gamma-OH, and the corresponding difference in negative-ion ESI-MS/MS was consistent with those previous findings.
    No preview · Article · Apr 2002 · Rapid Communications in Mass Spectrometry
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    Zhong-Zhou Chen · Bo Tan · Yan-Mei Li · Yi Chen · Chang-Mei Cheng · Yu-Fen Zhao
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    ABSTRACT: The biomimic reactions of N-phosphoryl amino acids are very important in the study of many biochemical processes. It was found that the α-COOH group, and not the γ-COOH, was involved in the ester exchange on phosphorus experimentally. The reactions, had been proposed to be related to intramolecular penta-coordinate phosphoric–carboxylic mixed anhydrides. N-Dimethylphosphoryl glutamic acid (DMP-Glu) was selected as model compound to study the reactivity difference between the α-COOH and γ-COOH group. From MNDO calculations, the energy of the penta-coordinate phosphoric intermediates containing five-membered ring from α-COOH was 40.8kJ/mol lower than that of the seven-membered one from γ-COOH. This result was in agreement with those from HF/6-31G∗∗ and B3LYP/6-31G∗∗ calculations. Theoretical three-dimensional potential energy surface of forming the intermediates predicted that the transition states 4 and 5 involving α-COOH or γ-COOH group had energy barriers of ΔE=196.1 and 216.9kJ/mol, respectively. So the α-COOH could be differentiated from γ-COOH intramolecularly in glutamic acid by N-phosphorylation.
    Preview · Article · Nov 2001 · Journal of Molecular Structure THEOCHEM