Insight into the interaction of heme with human calcitonin (hCT) and its inhibitory effect on hCT aggregation
(2026) In Journal of Inorganic Biochemistry 280.- Abstract
Human calcitonin (hCT) is a peptide hormone with therapeutic potential for bone-related disorders, yet its clinical application is hindered by a strong propensity to form amyloid fibrils. Strategies that effectively suppress hCT aggregation are therefore essential for enabling its reintroduction into pharmaceutical development. In our previous work, heme emerged as a potent inhibitor of hCT fibrillation via binding to the peptide. However, the molecular basis of this interaction and long-term inhibitory efficacy remain unclear. Herein, we systematically investigated heme-hCT binding and compared its anti-aggregation performance with a series of pharmaceutically relevant metalloporphyrins (FeTPPS, FeTBAP, FeTMPyP, MnTPPS, MnTBAP,... (More)
Human calcitonin (hCT) is a peptide hormone with therapeutic potential for bone-related disorders, yet its clinical application is hindered by a strong propensity to form amyloid fibrils. Strategies that effectively suppress hCT aggregation are therefore essential for enabling its reintroduction into pharmaceutical development. In our previous work, heme emerged as a potent inhibitor of hCT fibrillation via binding to the peptide. However, the molecular basis of this interaction and long-term inhibitory efficacy remain unclear. Herein, we systematically investigated heme-hCT binding and compared its anti-aggregation performance with a series of pharmaceutically relevant metalloporphyrins (FeTPPS, FeTBAP, FeTMPyP, MnTPPS, MnTBAP, MnTMPyP). Electrochemical and spectroscopic analyses revealed that heme binds with high affinity (Kb ≈ (3.67 ± 0.19) × 106 M−1) and 1:1 stoichiometry to the N-terminal region of hCT (residues 8–22), with His20 identified as the key binding site. Molecular calculations further illustrated that heme stabilizes hCT through multiple noncovalent interactions, including coordination with His20, π-π stacking with Phe22, and ionic interaction with Lys18. Long-term inhibition studies (up to 72 h) using thioflavin T fluorescence, circular dichroism, Nu-PAGE, and TEM demonstrated that heme persistently suppresses hCT fibrillation and maintains its monomeric conformation, outperforming all tested metalloporphyrins. A clear inhibitory hierarchy was observed: heme > > FeTPPS ≈ FeTBAP > MnTPPS ≈ MnTBAP > FeTMPyP > MnTMPyP, highlighting the importance of metal center, peripheral substituents, and electrostatic compatibility. These findings provide a mechanistic foundation for the design of heme-inspired molecular modulators aimed at improving the stability and pharmaceutical applicability of hCT, and other aggregation-prone peptide therapeutics.
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- author
- Ye, Huixian ; Xiao, Bin ; Wang, Hongxuan ; Zeng, Zijun ; Du, Jiayi ; Zhang, Shuya ; Liu, Siqin ; Chen, Hongmei ; Wu, Jinming LU and Sui, Yan
- organization
- publishing date
- 2026-07
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Aggregation inhibitors, Amyloid aggregation, Bone-related disorders, Heme, Human calcitonin
- in
- Journal of Inorganic Biochemistry
- volume
- 280
- article number
- 113319
- publisher
- Elsevier
- external identifiers
-
- pmid:41911648
- scopus:105034755074
- ISSN
- 0162-0134
- DOI
- 10.1016/j.jinorgbio.2026.113319
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
- id
- c2760407-ba3b-4778-b7bf-192b8d4f10d3
- date added to LUP
- 2026-05-25 15:58:50
- date last changed
- 2026-05-25 15:59:58
@article{c2760407-ba3b-4778-b7bf-192b8d4f10d3,
abstract = {{<p>Human calcitonin (hCT) is a peptide hormone with therapeutic potential for bone-related disorders, yet its clinical application is hindered by a strong propensity to form amyloid fibrils. Strategies that effectively suppress hCT aggregation are therefore essential for enabling its reintroduction into pharmaceutical development. In our previous work, heme emerged as a potent inhibitor of hCT fibrillation via binding to the peptide. However, the molecular basis of this interaction and long-term inhibitory efficacy remain unclear. Herein, we systematically investigated heme-hCT binding and compared its anti-aggregation performance with a series of pharmaceutically relevant metalloporphyrins (FeTPPS, FeTBAP, FeTMPyP, MnTPPS, MnTBAP, MnTMPyP). Electrochemical and spectroscopic analyses revealed that heme binds with high affinity (K<sub>b</sub> ≈ (3.67 ± 0.19) × 106 M−1) and 1:1 stoichiometry to the N-terminal region of hCT (residues 8–22), with His20 identified as the key binding site. Molecular calculations further illustrated that heme stabilizes hCT through multiple noncovalent interactions, including coordination with His20, π-π stacking with Phe22, and ionic interaction with Lys18. Long-term inhibition studies (up to 72 h) using thioflavin T fluorescence, circular dichroism, Nu-PAGE, and TEM demonstrated that heme persistently suppresses hCT fibrillation and maintains its monomeric conformation, outperforming all tested metalloporphyrins. A clear inhibitory hierarchy was observed: heme > > FeTPPS ≈ FeTBAP > MnTPPS ≈ MnTBAP > FeTMPyP > MnTMPyP, highlighting the importance of metal center, peripheral substituents, and electrostatic compatibility. These findings provide a mechanistic foundation for the design of heme-inspired molecular modulators aimed at improving the stability and pharmaceutical applicability of hCT, and other aggregation-prone peptide therapeutics.</p>}},
author = {{Ye, Huixian and Xiao, Bin and Wang, Hongxuan and Zeng, Zijun and Du, Jiayi and Zhang, Shuya and Liu, Siqin and Chen, Hongmei and Wu, Jinming and Sui, Yan}},
issn = {{0162-0134}},
keywords = {{Aggregation inhibitors; Amyloid aggregation; Bone-related disorders; Heme; Human calcitonin}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Journal of Inorganic Biochemistry}},
title = {{Insight into the interaction of heme with human calcitonin (hCT) and its inhibitory effect on hCT aggregation}},
url = {{http://dx.doi.org/10.1016/j.jinorgbio.2026.113319}},
doi = {{10.1016/j.jinorgbio.2026.113319}},
volume = {{280}},
year = {{2026}},
}