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Castriciano MA, Zagami R, Mazzaglia A, Romeo A, Monsù Scolaro L. A Kinetic Investigation of the Supramolecular Chiral Self-Assembling Process of Cationic Organometallic (2,2':6',2″-terpyridine)methylplatinum(II) Complexes with Poly(L-glutamic Acid). Int J Mol Sci 2024; 25:1176. [PMID: 38256248 PMCID: PMC10816852 DOI: 10.3390/ijms25021176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/15/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
The cationic platinum(II) organometallic complex [Pt(terpy)Me]+ (terpy = 2,2':6',2″-terpyridine) at mild acidic pH interacts with poly(L-glutamic acid) (L-PGA) in its α-helix conformation, affording chiral supramolecular adducts. Their kinetics of formation have been investigated in detail as a function of the concentrations of both reagents and changing pH, ionic strength, the length of the polymeric scaffold and temperature. After a very fast early stage, the kinetic traces have been analyzed as three consecutive steps, suggesting a mechanism based on the electrostatic fast formation of a not-organized aggregate that subsequently evolves through different rearrangements to form the eventual supramolecular adduct. A model for this species has been proposed based on (i) the attractive electrostatic interaction of the cationic platinum(II) complexes and the polyelectrolyte and (ii) the π-stacking interactions acting among the [Pt(terpy)Me]+ units.
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Affiliation(s)
- Maria Angela Castriciano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (M.A.C.); (R.Z.)
| | - Roberto Zagami
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (M.A.C.); (R.Z.)
| | - Antonino Mazzaglia
- CNR-ISMN Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy;
| | - Andrea Romeo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (M.A.C.); (R.Z.)
- CNR-ISMN Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy;
| | - Luigi Monsù Scolaro
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (M.A.C.); (R.Z.)
- CNR-ISMN Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V.le F. Stagno D’Alcontres, 31, 98166 Messina, Italy;
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Zagami R, Castriciano MA, Trapani M, Romeo A, Monsù Scolaro L. Interaction of Aromatic Amino Acids with Metal Complexes of Tetrakis-(4-Sulfonatophenyl)Porphyrin. Molecules 2024; 29:472. [PMID: 38257385 PMCID: PMC10819004 DOI: 10.3390/molecules29020472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/10/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
The interaction of a series of metal derivatives of 5, 10, 15, 20-tetrakis(4-sulfonato-phenyl)porphyrin (MTPPS4, M = Cu(II), Pt(II), Ni(II), Zn(II) and Co(II)), including the metal free porphyrin (TPPS4), with the aromatic amino acids L-tryptophan (L-Trp), L-and D-phenylalanine (L-and D-Phe) and L-histidine (L-His) have been investigated through UV/Vis spectroscopy. The amino acid L-serine (L-Ser) has been included as reference compound. The spectroscopic changes induced by adding the amino acids have been exploited to evaluate the extent of interaction between the molecular components in the supramolecular adducts. The binding constants have been estimated for most of the investigated systems, assuming a simple 1:1 equilibrium. The bathochromic shifts of the B-bands, the extent of hypochromicity and the binding constants have been analyzed through two chemical descriptors. All the data point to the important role played by the steric hindrance introduced by axial ligands coordinated to the metal ions and to the degree of hydrophobicity and size of the aromatic moiety in the amino acids.
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Affiliation(s)
- Roberto Zagami
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (R.Z.); (M.A.C.); (A.R.)
| | - Maria Angela Castriciano
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (R.Z.); (M.A.C.); (A.R.)
| | - Mariachiara Trapani
- CNR—ISMN Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy;
| | - Andrea Romeo
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (R.Z.); (M.A.C.); (A.R.)
- CNR—ISMN Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy;
| | - Luigi Monsù Scolaro
- Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy; (R.Z.); (M.A.C.); (A.R.)
- CNR—ISMN Istituto per lo Studio dei Materiali Nanostrutturati c/o Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, V. le F. Stagno D’Alcontres, 31, 98166 Messina, Italy;
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