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1. A noncanonical heme oxygenase specific for the degradation of c-type heme

   https://doi.org/10.1016/j.jbc.2021.100666  

   Li, Shuxin; Isiorho, Eta A.; Owens, Victoria L.; Donnan, Patrick H.; Odili, Chidinma L.; Mansoorabadi, Steven O. (January 2021, Journal of Biological Chemistry)
2. Heme dynamics and trafficking factors revealed by genetically encoded fluorescent heme sensors

   https://doi.org/10.1073/pnas.1523802113  

   Hanna, David A.; Harvey, Raven M.; Martinez-Guzman, Osiris; Yuan, Xiaojing; Chandrasekharan, Bindu; Raju, Gheevarghese; Outten, F. Wayne; Hamza, Iqbal; Reddi, Amit R. (July 2016, Proceedings of the National Academy of Sciences)
3. Controlling heme redox properties in peptide amphiphile fibers with sequence and heme loading ratio

   https://doi.org/10.1016/j.bpj.2024.05.021  

   Dutta, Chiranjit; Lopez, Virginia; Preston, Conner; Rudra, Nimesh; Chavez, Alex_Mauricio Valdivia; Rogers, Abigail M; Solomon, Lee A (July 2024, Biophysical Journal)

   Koder, Ronald (Ed.)

   Controlling the reduction midpoint potential of heme B is a key factor in many bioelectrochemical reactions, including long-range electron transport. Currently, there are a number of globular model protein systems to study this biophysical parameter; however, there are none for large polymeric protein model systems (e.g., the OmcS protein from G. sulfurreducens). Peptide amphiphiles, short peptides with a lipid tail that polymerize into fibrous structures, fill this gap. Here, we show a peptide amphiphile model system where one can tune the electrochemical potential of heme B by changing the loading ratio and peptide sequence. Changing the loading ratio resulted in the most significant increase, with values as high as −22 mV down to −224 mV. Circular dichroism spectra of certain sequences show Cotton effects at lower loading ratios that disappear as more heme B is added, indicating an ordered environment that becomes disrupted if heme B is overpacked. These findings can contribute to the design of functional self-assembling biomaterials. 

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4. Exploring the folding energy landscapes of heme proteins using a hybrid AWSEM-heme model

   https://doi.org/10.1007/s10867-021-09596-3  

   Chen, Xun; Lu, Wei; Tsai, Min-Yeh; Jin, Shikai; Wolynes, Peter G. (January 2022, Journal of Biological Physics)

   Abstract Heme is an active center in many proteins. Here we explore computationally the role of heme in protein folding and protein structure. We model heme proteins using a hybrid model employing the AWSEM Hamiltonian, a coarse-grained forcefield for the protein chain along with AMBER, an all-atom forcefield for the heme. We carefully designed transferable force fields that model the interactions between the protein and the heme. The types of protein–ligand interactions in the hybrid model include thioester covalent bonds, coordinated covalent bonds, hydrogen bonds, and electrostatics. We explore the influence of different types of hemes (heme b and heme c) on folding and structure prediction. Including both types of heme improves the quality of protein structure predictions. The free energy landscape shows that both types of heme can act as nucleation sites for protein folding and stabilize the protein folded state. In binding the heme, coordinated covalent bonds and thioester covalent bonds for heme c drive the heme toward the native pocket. The electrostatics also facilitates the search for the binding site. 

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5. Following Nature’s Footprint: Mimicking the High-Valent Heme-Oxo Mediated Indole Monooxygenation Reaction Landscape of Heme Enzymes

   https://doi.org/10.1021/jacs.1c11068  

   Mondal, Pritam; Rajapakse, Shanuk; Wijeratne, Gayan B. (March 2022, Journal of the American Chemical Society)