9HLK image
Entry Detail
PDB ID:
9HLK
Keywords:
Title:
X-ray structure of the adduct formed upon reaction of the diiodido analogue of picoplatin with lysozyme (structure A)
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2024-12-05
Release Date:
2025-05-14
Method Details:
Experimental Method:
Resolution:
1.96 Å
R-Value Free:
0.26
R-Value Work:
0.20
Space Group:
P 43 21 2
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Lysozyme C
Chain IDs:A (auth: AAA)
Chain Length:129
Number of Molecules:1
Biological Source:Gallus gallus
Primary Citation
Cytotoxicity and Binding to DNA, Lysozyme, Ribonuclease A, and Human Serum Albumin of the Diiodido Analog of Picoplatin.
Inorg.Chem. 64 8895 8905 (2025)
PMID: 40312957 DOI: 10.1021/acs.inorgchem.4c05424

Abstact

Here we investigated cytotoxicity and DNA and protein binding of an iodido analog of picoplatin, the cis-ammine-diiodido(2-methylpyridine)platinum(II) complex (I-picoplatin). I-picoplatin (IC50 = 3.7-12.4 μM) outperforms picoplatin (IC50 = 11.8-22.6 μM) in the human cancer cell lines used and shows a greater ability to overcome the cisplatin resistance of A2780 ovarian cancer cells than does picoplatin. I-picoplatin also induces different cell cycle changes (reduced S-phase fraction and an increase in the G2/M phase arrest) in HeLa cervical carcinoma cells compared to both picoplatin and cisplatin. Binding of the metal compound to DNA model systems was investigated by ethidium bromide displacement assay and circular dichroism. Its reactivity with lysozyme (HEWL) and pancreatic RNase A was studied by X-ray diffraction and mass spectrometry experiments. I-picoplatin binds the DNA double helix and is able to retain the 2-methylpyridine ligand and at least one of the two iodido ligands when bound to the two proteins. Various Pt-containing moieties, including one based on the isomerized structure of I-picoplatin, coordinate the His and Met residues. A low-resolution structure of the I-picoplatin/human serum albumin (HSA) adduct has also been solved. The side chains of His146, Met289, and Met329 are the primary binding sites of the I-picoplatin moieties on HSA.

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