Abstract

A workable approach named xTB-sTDDFT was selected to investigate the excited-state spectra of oxytocin (135 atoms), GHRP-6 (120 atoms) and insulin (793 atoms). Three different Hartree–Fock components functionals (wB97XD3: 51%, LC-BLYP: 53%, wB97X: 57%) were used to calculate the excitation spectra, and the results calculated by wB97XD3 functional well agree with the experiments. It’s a deep impression that computed time cost reduced by more than 80%. For polypeptide (oxytocin and GHRP-6), both UV and fluorescence spectra were obtained, and the errors between the calculated and experimental values approximately were 20 nm. For Insulin, the errors are within 15 nm. UV spectrum peak is λ_cal = 262 nm (λ_exp = 277 nm, Δλ = 15 nm), and fluorescence spectrum peak is λ_cal = 294 nm (λ_exp = 304 nm, Δλ = 10 nm). In summary, a suitable theoretical model is established to ultra-fast calculate the electronic excitation spectra of large systems, such as proteins and biomacromolecules, with good calculation accuracy, fast calculation speed and low cost.

Graphic abstract

中文翻译：

---

超快速计算大型系统的激发态光谱：蛋白质的紫外和荧光光谱

摘要

选择了一种名为 xTB-sTDDFT 的可行方法来研究催产素（135 个原子）、GHRP-6（120 个原子）和胰岛素（793 个原子）的激发态光谱。三种不同的 Hartree-Fock 组件泛函（wB97XD3：51%，LC-BLYP：53%，wB97X：57%）用于计算激发光谱，wB97XD3 泛函计算的结果与实验非常吻合。计算时间成本降低了 80% 以上，给人留下了深刻的印象。对于多肽（催产素和GHRP-6），获得了紫外和荧光光谱，计算值与实验值之间的误差约为20 nm。对于胰岛素，误差在 15 nm 以内。紫外光谱峰为λ _cal  = 262 nm ( λ _exp  = 277 nm, Δ λ = 15 nm），荧光光谱峰为λ _cal  = 294 nm（λ _exp  = 304 nm，Δ λ  = 10 nm）。综上所述，建立了合适的理论模型来超快速计算蛋白质和生物大分子等大型系统的电子激发光谱，具有计算精度好、计算速度快、成本低的特点。

图形摘要