- Functional identification and structure determination of two novel prolidases from cog1228 in the amidohydrolase superfamily
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Two uncharacterized enzymes from the amidohydrolase superfamily belonging to cog1228 were cloned, expressed, and purified to homogeneity. The two proteins, Sgx9260c (gi|44242006) and Sgx9260b (gi|44479596), were derived from environmental DNA samples originating from the Sargasso Sea. The catalytic function and substrate profiles for Sgx9260c and Sgx9260b were determined using a comprehensive library of dipeptides and N-acyl derivative of l-amino acids. Sgx9260c catalyzes the hydrolysis of Gly-l-Pro, l-Ala-l-Pro, and N-acyl derivatives of l-Pro. The best substrate identified to date is N-acetyl-l-Pro with a value of kcat/Km of 3 × 105 M -1 s-1. Sgx9260b catalyzes the hydrolysis of l-hydrophobic l-Pro dipeptides and N-acyl derivatives of l-Pro. The best substrate identified to date is N-propionyl-l-Pro with a value of kcat/Km of 1 × 105 M-1 s-1. Three-dimensional structures of both proteins were determined by X-ray diffraction methods (PDB codes 3MKV and 3FEQ). These proteins fold as distorted (β/α) 8-barrels with two divalent cations in the active site. The structure of Sgx9260c was also determined as a complex with the N-methylphosphonate derivative of l-Pro (PDB code 3N2C). In this structure the phosphonate moiety bridges the binuclear metal center, and one oxygen atom interacts with His-140. The α-carboxylate of the inhibitor interacts with Tyr-231. The proline side chain occupies a small substrate binding cavity formed by residues contributed from the loop that follows β-strand 7 within the (β/α)8-barrel. A total of 38 other proteins from cog1228 are predicted to have the same substrate profile based on conservation of the substrate binding residues. The structure of an evolutionarily related protein, Cc2672 from Caulobacter crecentus, was determined as a complex with the N-methylphosphonate derivative of l-arginine (PDB code 3MTW).
- Xiang, Dao Feng,Patskovsky, Yury,Xu, Chengfu,Fedorov, Alexander A.,Fedorov, Elena V.,Sisco, Abby A.,Sauder, J. Michael,Burley, Stephen K.,Almo, Steven C.,Raushel, Frank M.
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experimental part
p. 6791 - 6803
(2011/05/05)
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- Endomorphin-1 analogs with enhanced metabolic stability and systemic analgesic activity: Design, synthesis, and pharmacological characterization
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We synthesized four new analogs of endomorphin-1 by systematic chemical modifications. To identify the best possible drug candidates for clinical pain management and to investigate the potential contribution of these alterations to the biological activity, their pharmacological properties were determined. All of the analogs showed significantly enhanced metabolic stability. The fact that centrally mediated analgesia following peripheral administration was observed with one of the analogs suggested the approach design undertaken here had validity in the development of endomorphin-1 as a successful opioid drug for the clinic.
- Liu, Hongmei,Zhang, Bangzhi,Liu, Xuefeng,Wang, Changlin,Ni, Jingman,Wang, Rui
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p. 1694 - 1702
(2008/02/03)
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- Synthesis and anti-inflammatory activity of acetylsalicylamino acids and peptides
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Several water-soluble acetylsalicylamino acids and peptides containing neutral and acidic amino acids were synthesized and investigated for anti-inflammatory activity. 2006 Springer Science+Business Media, Inc.
- Khalikov,Kodirov,Alieva
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p. 204 - 207
(2008/02/01)
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- Degradation of azaglycinamido residues in model tripeptides derived from goserelin
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Three model tripeptides, N-acetyl-Tyr-Pro-azaGly-NH2 (NYPaG), Tyr-Pro- azaGly-NH2 (YPaG), and Tyr-Pro-Gly-NH2(YPG), were subjected to a systematic degradation study to get information about the degradation of the azaglycinamido residue The degradation products were characterized with LC- MS. Main degradation products of NYPaG possess partially or totally eliminated azaglycinamido residues, while YPaG and YPG are exhibit cyclo(Tyr- Pro) formation, a diketopiperazine. The influence of the pH on the degradation rate constant k(obs) was investigated for NYPaG and YPaG in the pH range 0.4-11. An U-shaped profile with an inflexion around pH 9 was found for NYPaG while the degradation rate of YPaG was independent of the pH. NYPaG apparently was subject to proton-, solvent-, and hydroxyl-catalyzed degradation reactions whereas YPaG only underwent solvent-catalyzed reactions. Some influence of acetate and phosphate ions on k(obs) was found for YPaG. Arrhenius plots of NYPaG and YPaG were found to be linear. (C) 2000 Wiley-Liss, Inc.
- Hoitink, Marnix A.,Beijnen, Jos H.,Bult, Auke,Damen, J. Mirjam A.,Van Der Houwen, Oeds A. G. J.,Kruijtzer, John A. W.,Tibben, Matthijs M.,Wiese, Gerard,Underberg, Willy J. M.
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p. 108 - 114
(2007/10/03)
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- Catalytic properties of X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis subsp. cremoris nTR.
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An X-prolyl dipeptidyl aminopeptidase (X-PDAP; EC 3.4.14.5) was identified to be loosely bound on the inner cell membrane fraction of Lactococcus lactis subsp. cremoris nTR. The biosynthesis of X-PDAP was continuously increased before the late-log growth phase of the bacteria. Both Gly-Pro-pNA and Ala-Ala-pNA were hydrolyzed by X-PDAP; the kcat/Km value of the former was about 10-fold that of the latter. The Ki of X-Pro and Pro-X were more specific to X-PDAP than those of X-Ala. The enzyme splitting a dipeptide sequentially from beta-casomorphin as a model catalytic pattern was identified and some properties of the enzyme were further characterized.
- Yan,Ho,Hou
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p. 704 - 707
(2007/10/02)
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