Copper complexes of dipeptides with l-Lys as C-terminal residue: a thermodynamic and spectroscopic study

Remelli, Maurizio; Conato, Chiara; Agarossi, Alessandra; Pulidori, F.; Młynarz, Piotr; Kozłowski, Henryk

doi:10.1016/s0277-5387(00)00539-8

Cited by 23 publications

(28 citation statements)

References 30 publications

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“…The terminal carboxylic group is deprotonated over the explored pH range and the corresponding equilibrium is not considered throughout. The thermodynamic results are in good agreement with literature data on analogous ligands, [11,12,14,15] within experimental errors. Figure 2.…”

Section: Resultssupporting

confidence: 89%

“…Although the NMR spectroscopic data refer to a slight excess of ligand, and they cannot be directly transferred to the equimolar solutions discussed above, the distinct effect of Cu II ions on the protons of both His residues (see Figure 5) strongly supports the involvement of two imidazoles in the metal coordination at acidic pHs. The obtained complex is similar to that formed by the protected peptide, [11] except for the involvement of the negatively charged carboxylate of adjacent 14 Asp in the coordination sphere. In addition, molecular mechanics calculations [23] performed on the Cu II / TLEGTKKGHKLHLDY complex with the suggested {2N Im , O Ϫ } donor set gave the low energy structures shown in Figure 9.…”

mentioning

confidence: 53%

“…However, such effects could be observed only at relatively high Cu II /peptide ratios (especially at pH Ͼ 7.0), much higher than is usual in NMR experiments on Cu II complexes. As shown in Figure 5, the paramagnetic effects at pH 5.6 were mainly detected on 9 His and 12 His aromatic protons, on the His H β and on the 14 Asp H β .…”

Section: ϫ3mentioning

confidence: 90%

“…The signals that underwent the largest broadening were those of His and 1 Thr residues, but, to a lesser extent, the 14 Asp, 6,7,10 Lys, and 15 Tyr residues were also affected. Similarly, the most affected relaxation rates were those of the His resi- …”

Section: ϫ3mentioning

confidence: 94%

“…[11] In the second complex the N-terminal group acts as an anchoring point and copper is bound to the amino nitrogen of 1 Thr and to the three amide nitrogens of the following residues ( 2 Leu, 3 Glu, 4 Gly). Moreover the effects measured on R 1p of 12 His, 14 Asp and 15 Tyr may result from the accumulation of the negative charges on the C-terminal side of the peptide (Tyr-O Ϫ , Asp-COO Ϫ ) and their proximity to paramagnetic centre.…”

mentioning

confidence: 99%

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Cu^II Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

et al. 2003

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The complex-formation equilibria of the pentadecapeptide TLEGTKKGHKLHLDY, the 114-128 protein fragment of SPARC, with the Cull ion have been investigated, at I = 0.1 mol.dm(-3) (KNO3) and T = 298.2 K. Protonation and complex-formation constants have been determined potentiometrically, and formation enthalpies measured by direct solution calorimetry; the complex-formation model and species stoichiometry have been carefully checked by means of UV/Vis absorption, CD and EPR spectroscopy. The structure hypo-theses of the complex species are also based on detailed study of the H-1 and C-13 NMR spectra of the ligand in both the absence and presence of copper ions. The involvement in complex-formation of both the terminal amino and imidazole groups has been suggested and their specific behaviour at different pH values elucidated

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Section: Resultssupporting

confidence: 89%

mentioning

confidence: 53%

Section: ϫ3mentioning

confidence: 90%

Section: ϫ3mentioning

confidence: 94%

mentioning

confidence: 99%

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Cu^II Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

et al. 2003

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Probing of C‐terminal lysine variation in a recombinant monoclonal antibody production using Chinese hamster ovary cells with chemically defined media

Luo

Zhang

Ren

et al. 2012

Biotech & Bioengineering

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C-terminal lysine (C-K) variants are commonly observed in therapeutic monoclonal antibodies and recombinant proteins. Heterogeneity of C-K residues is believed to result from varying degree of proteolysis by endogenous carboxypeptidase(s) during cell culture production. The achievement of batch-to-batch culture performance and product quality reproducibility is a key cell culture development criterion. Understanding the operational parameters affecting C-K levels provides valuable insight into the cell culture process. A CHO cell line X expressing a recombinant antibody was selected as the model cell line due to the exhibited sensitivity of its C-K level to the process conditions. A weak cation exchange chromatography (WCX) method with or without carboxypeptidase B (CpB) treatment was developed to monitor the C-K level for in-process samples. The effects of operating conditions (i.e., temperature and culture duration) and media trace elements (copper and zinc) on C-K variants were studied. The dominant effect on C-K level was identified as the trace elements concentration. Specifically, increased C-K levels were observed with increase of copper concentration and decrease of zinc concentration in chemically defined medium. Further, a hypothesis for C-K processing with intracellular and extracellular carboxypeptidase activity was proposed, based on preliminary intracellular carboxypeptidase Western blot results and the extracellular HCCF holding study.

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Advances in chiral separations of small peptides by capillary electrophoresis and chromatography

Ali

ALOthman

Al–Warthan

et al. 2014

J of Separation Science

133

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Many chemical and biological processes are controlled by the stereochemistry of small polypeptides (di-, tri-, tetra-, penta-, hexapeptides, etc). The biological importance of peptide stereoisomers is of great value. Therefore, the chiral resolution of peptides is an important issue in biological and medicinal sciences and drug industries. The chiral resolutions of peptide racemates have been discussed with the use of capillary electrophoresis and chromatographic techniques. The various chiral selectors used were polysaccharides, cyclodextrins, Pirkle types, macrocyclic antibiotics, crown ethers, imprinted polymers, etc. The stereochemistry of dipeptides is also discussed. Besides, efforts are made to explain the chiral recognition mechanisms, which will be helpful in understanding existing and developing new stereoselective analyses. Future perspectives of enantiomeric resolution are also predicted. Finally, the review concludes with the demand of enantiomeric resolution of all naturally occurring and synthetic peptides.

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Copper complexes of dipeptides with l-Lys as C-terminal residue: a thermodynamic and spectroscopic study

Cited by 23 publications

References 30 publications

Cu^II Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

Cu^II Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

Probing of C‐terminal lysine variation in a recombinant monoclonal antibody production using Chinese hamster ovary cells with chemically defined media

Advances in chiral separations of small peptides by capillary electrophoresis and chromatography

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Copper complexes of dipeptides with l-Lys as C-terminal residue: a thermodynamic and spectroscopic study

Cited by 23 publications

References 30 publications

CuII Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

CuII Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

Probing of C‐terminal lysine variation in a recombinant monoclonal antibody production using Chinese hamster ovary cells with chemically defined media

Advances in chiral separations of small peptides by capillary electrophoresis and chromatography

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Product

Resources

About

Cu^II Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors

Cu^II Ion Coordination to an Unprotected Pentadecapeptide Containing Two His Residues: Competition Between the Terminal Amino and the Side‐Chain Imidazole Nitrogen Donors