A spectroscopic study of soybean peroxidase (SBP) has been carried out using electronic absorption, resonance Raman (RR) and electron paramagnetic resonance (EPR) spectroscopy in order to determine the effects of temperature on the heme spin state. Upon lowering the temperature a transition from high spin to low spin is induced in SBP resulting from conformational changes in the heme cavity, including a contraction of the heme core, the reorientation of the vinyl group in position 2 of the porphyrin macrocycle, and the binding of the distal His to the Fe atom. Moreover, the combined analysis of the data derived from the different techniques at both room and low temperatures demonstrates that at low temperature the quantum-mechanically admixed spin state (QS) of SBP has RR frequencies different from those observed for the QS species at room temperature.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0162-0134(99)00156-7 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Modulation of Co spin state at CoO crystalline-amorphous interfaces for CO oxidation and NO decomposition.
Nat Commun
January 2025
School of Environment, Tsinghua University, Beijing, 100084, P. R. China.
Modulation of electronic spin states in cobalt-based catalysts is an effective strategy for molecule activations. Crystalline-amorphous interfaces often exhibit unique catalytic properties due to disruptions of long-range order and alterations in electronic structure. However, the mechanisms of molecule activation and spin states at interfaces remain elusive.
View Article and Find Full Text PDFThe moral voice in addiction and the self.
J Subst Use Addict Treat
January 2025
Department of Criminology, Bar-Ilan University, Ramat Gan, Israel.
Background: The robust literature on moral psychology research has often overlooked people struggling with addiction, partly due to social, theoretical, and methodological biases. This has created a gap in understanding the role of moral thinking and its influence on addiction and recovery. To address this, our hermeneutic phenomenological study, the first in a series, explores the moral voice of individuals contending with addiction.
View Article and Find Full Text PDFMechanisms of epigallocatechin-3-gallate-loaded metal-organic framework in preventing oxidative degradation of shrimp (Litopenaeus vannamei) surimi gel.
Food Chem
January 2025
Shenzhen Key Laboratory of Food Nutrition and Health, Guangdong Engineering Technology Research Center of Aquatic Food Processing and Safety Control, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China; State Key Laboratory of Marine Food Processing & Safety Control, National Engineering Research Center of Seafood, Collaborative Innovation Center of Seafood Deep Processing, School of Food Science and Technology, Dalian Polytechnic University, Dalian 116034, China. Electronic address:
This work aimed to elucidate the deterioration mechanisms of shrimp surimi gels during refrigerated storage, and the regulatory mechanisms of epigallocatechin-3-gallate loaded cyclodextrin-based metal-organic framework (EGCG@CD-MOF) as a model antioxidant. Labele-free proteomics provided a quantitative analysis of the differential proteomic signatures of degraded proteins. Structural proteins, like myosin, paramyosin, titin, laminin, and α-actinin, along with calcium regulatory proteins, like calcineurin and sarcoplasmic calcium-binding protein were found to be highly susceptible to oxidative degradation during refrigeration.
View Article and Find Full Text PDFSpin-Orbit Coupling and Admixture Coefficients in SA-CASSCF and MS-CASPT2, and Triplet Excitation Yield Simulated via Trajectory Surface Hopping and Calibrated SA-CASSCF in 1,2-Dioxetane Derivatives.
J Phys Chem A
January 2025
Department of Chemistry and Supercomputing Institute, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States.
The energy gaps, spin-orbit coupling (SOC), and admixture coefficients over a series of the configurations are evaluated by the SA-CASSCF/6-31G, SA-CASSCF/6-31G*, SA-CASSCF/ANO-RCC-VDZP, and MS-CASPT2/ANO-RCC-VDZP to reveal the extent of the inaccuracy of the SA-CASSCF. By comparing the mean absolute errors for the energy gaps and the admixture coefficient magnitudes (ACMs) measured between the SA-CASSCF/6-31G, SA-CASSCF/6-31G*, or SA-CASSCF/ANO-RCC-VDZP and the MS-CASPT2/ANO-RCC-VDZP, the SA-CASSCF/6-31G is selected as the electronic structure method in the nonadiabatic molecular dynamics simulation. The major components of the ACMs of the SA-CASSCF/6-31G and MS-CASPT2/ANO-RCC-VDZP are identified and compared; we find that the ACMs are underestimated by the SA-CASSCF/6-31G, which is verified by the reasonable triplet quantum yield simulated by the trajectory surface hopping and the calibrated SA-CASSCF/6-31G.
View Article and Find Full Text PDFCathodic tandem alkylation/dearomatization of heterocycles enabled by Al-facilitated carbonyl deoxygenation.
Nat Commun
January 2025
School of Environmental and Chemical Engineering, Wuyi University, Jiangmen, PR China.
Developing efficient strategies for the deoxygenative functionalization of carbonyl compounds is crucial for enhancing the effective utilization of biomass and the upgrading of chemical feedstocks. In this study, we present an elegant cathodic reduction strategy that enables a tandem alkylation/dearomatization reaction between quinoline derivatives and aryl aldehydes/ketones in a one-pot process. Our approach can be executed via two distinct paths: the aluminum (Al)-facilitated spin-center shift (SCS) path and the Al-facilitated direct deoxygenation path.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!