@article {48315,
	title = {Interactive study of Au-20 nanocluster and methyl substituted amide linked tyrosine/tryptophan to develop representative model for studying protein-nanoparticle interaction},
	journal = {Journal of Molecular Structure},
	volume = {1272},
	year = {2023},
	month = {JAN},
	pages = {134177},
	type = {Article},
	abstract = {<p>
	Investigations on UV-vis, steady-state fluorescence and synchronous fluorescence properties of human hemoglobin (HHb) reveals greater spectral shifts in peaks arising due to alterations in microenvironment of Tyr-compared to Trp-during interactions with gold nanoparticle (GNP). Besides, interactions of Au-20 nanocluster with modified Tyr/Trp (possessing methyl substituted amide bonds) by quantum chemical calculations demonstrate significant role of amide bonds and the spectral shift, binding energy and alteration in bond distances appear to be higher for modified Tyr-compared to modified Trp. Moreover, close resemblance of frequency shift of modified Tyr/Trp-in presence of Au 20 is observed with respect to the experimental FT-IR study of HHb upon interaction with GNP, suggesting participation of amide bonds in both cases. Furthermore, CD DFT calculations using optimized helical stretch of HHbin presence of Au-20 and experimental CD results of HHb in presence of GNP further indicate participation amide bonds and biocompatibility of GNP. Apparently, the theoretical and experimental interactions are going in good agreement with each other. Overall, the study of interactions of modified Tyr/Trp-as representative models of protein microenvironment and Au-20 nanocluster as prototype of GNP to develop models for exploring protein nanoparticle interactions has been highlighted. (C) 2022 Elsevier B.V. All rights reserved.</p>
},
	keywords = {amide bonds, Au-20 nanocluster, Gold nanoparticle, Human hemoglobin, Modified Tyr/Trp},
	issn = {0022-2860},
	doi = {10.1016/j.molstruc.2022.134177},
	author = {Sen Banerjee, Nineesha and Ghosh, Deborin and Mitra, Ishani and Paul, Somnath and Show, Bibhutibhushan and Ganguly, Tapan and Chakraborty, Madhurima}
}
@article {49919,
	title = {Revealing the functional importance of tyrosine and tryptophan of human hemoglobin for development of structural templates representing protein microenvironment},
	journal = {Computational and Theoretical Chemistry},
	volume = {1254},
	year = {2025},
	month = {DEC},
	pages = {115483},
	type = {Article},
	abstract = {<p>
	Microenvironment surrounding Tyrosine (Tyr) / Tryptophan (Trp) and heme appear to characterize the UV-vis absorption spectra of human hemoglobin (HHb). Structural elucidation of HHb using multiple tools, that may contribute to its spectral properties, then indicate greater structural stability of subunit A and the significance of its heme, Tyr42 and Trp14. Mutagenesis of Tyr42 and Trp14 of subunit A to Glycine (Gly) further validate their contribution in determining the structural stability, physicochemical properties, functional properties, and secondary structure of HHb. Accordingly, the use of structural coordinates of Tyr42 and heme as the first cluster and Trp14, Tyr42 and heme as the second cluster to represent the microenvironment of HHb is assessed for the first time. The calculated (DFT) absorption and FTIR properties of both the clusters are in well agreement with experimental absorption and FTIR characteristics of whole HHb suggesting prospective biomedical applications of these clusters.</p>
},
	keywords = {Heme, Human hemoglobin, Nano-peptide cluster, Representative template, Trp14, Tyr42},
	issn = {2210-271X},
	doi = {10.1016/j.comptc.2025.115483},
	author = {Chakraborty, Madhurima and Sen Banerjee, Nineesha and Ghosh, Deborin and Bhattacharya, Prabuddha and Ganguly, Tapan}
}
