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de Armiño DJA, Di Lella S, Montepietra D, Delcanale P, Bruno S, Giordano D, Verde C, Estrin DA, Viappiani C, Abbruzzetti S. Kinetic and dynamical properties of truncated hemoglobins of the Antarctic bacterium Pseudoalteromonas haloplanktis TAC125. Protein Sci 2024; 33:e5064. [PMID: 38864722 PMCID: PMC11168075 DOI: 10.1002/pro.5064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/07/2024] [Accepted: 05/14/2024] [Indexed: 06/13/2024]
Abstract
Due to the low temperature, the Antarctic marine environment is challenging for protein functioning. Cold-adapted organisms have evolved proteins endowed with higher flexibility and lower stability in comparison to their thermophilic homologs, resulting in enhanced reaction rates at low temperatures. The Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 (PhTAC125) genome is one of the few examples of coexistence of multiple hemoglobin genes encoding, among others, two constitutively transcribed 2/2 hemoglobins (2/2Hbs), also named truncated Hbs (TrHbs), belonging to the Group II (or O), annotated as PSHAa0030 and PSHAa2217. In this work, we describe the ligand binding kinetics and their interrelationship with the dynamical properties of globin Ph-2/2HbO-2217 by combining experimental and computational approaches and implementing a new computational method to retrieve information from molecular dynamic trajectories. We show that our approach allows us to identify docking sites within the protein matrix that are potentially able to transiently accommodate ligands and migration pathways connecting them. Consistently with ligand rebinding studies, our modeling suggests that the distal heme pocket is connected to the solvent through a low energy barrier, while inner cavities play only a minor role in modulating rebinding kinetics.
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Affiliation(s)
- Diego Javier Alonso de Armiño
- Departamento de Química Inorgánica, Analítica y Química Física, and INQUIMAE‐CONICET, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Ciudad UniversitariaBuenos AiresArgentina
| | - Santiago Di Lella
- Departamento de Química Biológica and IQUIBICEN‐CONICET, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Ciudad UniversitariaBuenos AiresArgentina
| | - Daniele Montepietra
- Department of Chemistry, Life Sciences and Environmental SustainabilityUniversity of ParmaParmaItaly
- Nanoscience Institute—CNR‐NANOModenaItaly
| | - Pietro Delcanale
- Department of Mathematical, Physical and Computer SciencesUniversity of ParmaParmaItaly
| | - Stefano Bruno
- Department of Food and Drug SciencesUniversity of ParmaParmaItaly
| | - Daniela Giordano
- Institute of Biosciences and BioResources (IBBR), CNRNaplesItaly
- Department of Ecosustainable Marine BiotechnologyStazione Zoologica Anton DohrnNaplesItaly
| | - Cinzia Verde
- Institute of Biosciences and BioResources (IBBR), CNRNaplesItaly
- Department of Ecosustainable Marine BiotechnologyStazione Zoologica Anton DohrnNaplesItaly
| | - Dario A. Estrin
- Departamento de Química Inorgánica, Analítica y Química Física, and INQUIMAE‐CONICET, Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires, Ciudad UniversitariaBuenos AiresArgentina
| | - Cristiano Viappiani
- Department of Mathematical, Physical and Computer SciencesUniversity of ParmaParmaItaly
| | - Stefania Abbruzzetti
- Department of Mathematical, Physical and Computer SciencesUniversity of ParmaParmaItaly
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Martinez Grundman JE, Johnson EA, Lecomte JTJ. Architectural digest: Thermodynamic stability and domain structure of a consensus monomeric globin. Biophys J 2023; 122:3117-3132. [PMID: 37353934 PMCID: PMC10432219 DOI: 10.1016/j.bpj.2023.06.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 06/13/2023] [Accepted: 06/20/2023] [Indexed: 06/25/2023] Open
Abstract
Artificial proteins representing the consensus of a set of homologous sequences have attracted attention for their increased thermodynamic stability and conserved activity. Here, we applied the consensus approach to a b-type heme-binding protein to inspect the contribution of a dissociable cofactor to enhanced stability and the chemical consequences of creating a generic heme environment. We targeted the group 1 truncated hemoglobin (TrHb1) subfamily of proteins for their small size (∼120 residues) and ease of characterization. The primary structure, derived from a curated set of ∼300 representative sequences, yielded a highly soluble consensus globin (cGlbN) enriched in acidic residues. Optical and NMR spectroscopies revealed high-affinity heme binding in the expected site and in two orientations. At neutral pH, proximal and distal iron coordination was achieved with a pair of histidine residues, as observed in some natural TrHb1s, and with labile ligation on the distal side. As opposed to studied TrHb1s, which undergo additional folding upon heme binding, cGlbN displayed the same extent of secondary structure whether the heme was associated with the protein or not. Denaturation required guanidine hydrochloride and showed that apo- and holoprotein unfolded in two transitions-the first (occurring with a midpoint of ∼2 M) was shifted to higher denaturant concentration in the holoprotein (∼3.7 M) and reflected stabilization due to heme binding, while the second transition (∼6.2 M) was common to both forms. Thus, the consensus sequence stabilized the protein but exposed the existence of two separately cooperative subdomains within the globin architecture, masked as one single domain in TrHb1s with typical stabilities. The results suggested ways in which specific chemical or thermodynamic features may be controlled in artificial heme proteins.
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Affiliation(s)
| | - Eric A Johnson
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland
| | - Juliette T J Lecomte
- T.C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, Maryland.
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Bao C, Li M, Zhao X, Shi J, Liu Y, Zhang N, Zhou Y, Ma J, Chen G, Zhang S, Chen H. Mining of key genes for cold adaptation from Pseudomonas fragi D12 and analysis of its cold-adaptation mechanism. Front Microbiol 2023; 14:1215837. [PMID: 37485517 PMCID: PMC10358777 DOI: 10.3389/fmicb.2023.1215837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 06/21/2023] [Indexed: 07/25/2023] Open
Abstract
The psychrotroph Pseudomonas fragi D12, which grew strongly under low temperatures, was screened from tundra soil collected from the permanent alpine zone on Changbai Mountain. To mine the genes critical for cold tolerance and to investigate the cold-adaptation mechanism, whole-genome sequencing, comparative genomic analysis, and transcriptome analysis were performed with P. fragi. A total of 124 potential cold adaptation genes were identified, including nineteen unique cold-adaptive genes were detected in the genome of P. fragi D12. Three unique genes associated with pili protein were significantly upregulated at different degrees of low temperature, which may be the key to the strong low-temperature adaptability of P. fragi D12. Meanwhile, we were pleasantly surprised to find that Pseudomonas fragi D12 exhibited different cold-adaptation mechanisms under different temperature changes. When the temperature declined from 30°C to 15°C, the response included maintenance of the fluidity of cell membranes, increased production of extracellular polymers, elevation in the content of compatibility solutes, and reduction in the content of reactive oxygen species, thereby providing a stable metabolic environment. When the temperature decreased from 15°C to 4°C, the response mainly included increases in the expression of molecular chaperones and transcription factors, enabling the bacteria to restore normal transcription and translation. The response mechanism of P. fragi D12 to low-temperature exposure is discussed. The results provide new ideas for the cold-adaptation mechanism of cold-tolerant microorganisms.
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Affiliation(s)
- Changjie Bao
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Muzi Li
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Xuhui Zhao
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Jia Shi
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Yehui Liu
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Na Zhang
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Yuqi Zhou
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Jie Ma
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Guang Chen
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Sitong Zhang
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
- Key Laboratory of Mollisols Agroecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun, China
| | - Huan Chen
- Key Laboratory of Straw Comprehensive Utilization and Black Soil Conservation, Ministry of Education, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
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Laye VJ, DasSarma S. Double mutations far from the active site affect cold activity in an Antarctic halophilic β-galactosidase. Protein Sci 2022; 31:677-687. [PMID: 34939242 PMCID: PMC8862438 DOI: 10.1002/pro.4264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 12/16/2021] [Accepted: 12/17/2021] [Indexed: 11/09/2022]
Abstract
The Antarctic haloarchaeon, Halorubrum lacusprofundi, contains a polyextremophilic family 42 β-galactosidase, which we are using as a model for cold-active enzymes. Divergent amino acid residues in this 78 kDa protein were identified through comparative genomics and hypothesized to be important for cold activity. Six amino acid residues were previously mutated and five were shown by steady-state kinetic analysis to have altered temperature-dependent catalytic activity profiles via effects on Km and/or kcat compared to the wild-type enzyme. In this follow-up study, double-mutated enzymes were constructed and tested for temperature effects, including two new tandem residue pairs (N180T/A181T and T383A/S384A), and pairwise combination of the single residue mutations (N251D, F387L, I476V, and V482L). All double-mutated enzymes were found to be more catalytically active at moderate and/or less active at colder temperatures than wild-type, with both Km and kcat effects observed for the two tandem mutations. For pairwise combinations, a Km effect was seen when the surface exposed F387L mutation located in a domain A TIM barrel α helix 19 Å from the active site was combined with two internal residues, N251D or V482L. When another surface exposed mutation I476V located in a coiled region of domain B 25 Å from the active site was paired with N251D or V482L, a kcat effect was observed. These results indicate that temperature-dependent kinetic effects may be complex and subtle and are mediated by a combination of a small number of residues distant from the active site via changes to the hydration shell and/or perturbation of internal packing.
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Affiliation(s)
- Victoria J. Laye
- Institute of Marine and Environmental TechnologyUniversity System of MarylandBaltimoreMarylandUSA,Department of Microbiology and ImmunologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Shiladitya DasSarma
- Institute of Marine and Environmental TechnologyUniversity System of MarylandBaltimoreMarylandUSA,Department of Microbiology and ImmunologyUniversity of Maryland School of MedicineBaltimoreMarylandUSA
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Hydrogen gas as a central on-off functional switch of reversible metabolic arrest - New perspectives for biotechnological applications. J Biotechnol 2021; 335:9-18. [PMID: 34090950 DOI: 10.1016/j.jbiotec.2021.06.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 05/09/2021] [Accepted: 06/01/2021] [Indexed: 11/23/2022]
Abstract
Metabolism is the sum of all chemical reactions that sustain life. There is an ongoing effort to control metabolic rate, which correlates with the maximum lifespan potential and constitutes one of the oldest scientific questions. Herein, we report on the complete reversible arrest of cellular metabolism and cell growth in a series of organisms, from microalgae to yeast upon exposure to a 100 % hydrogen atmosphere. We also report a tolerance of the microalgae under these conditions against extreme stress conditions, like high salt concentrations. The addition of oxygen or air almost completely restores the metabolic rate and cell growth. Molecular dynamics simulations are employed to decipher this phenomenon at atomic scale. Various proteins, including photosynthetic and respiratory complexes (LHCII, cytochrome c5) are probed in the interaction with hydrogen. Exposure to hydrogen, as opposed to oxygen, decreases the fluctuations of protein residues indicating thermostability. According to the above mechanism, an absolute hydrogen atmosphere can preserve biological products (e.g. fruits) for a long time without consuming any energy. By combining biological, chemical and computational methods, in this research we provide the basis for future innovative studies and advances in the field of biotechnology.
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Unusually Fast bis-Histidyl Coordination in a Plant Hemoglobin. Int J Mol Sci 2021; 22:ijms22052740. [PMID: 33800498 PMCID: PMC7962945 DOI: 10.3390/ijms22052740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/16/2021] [Accepted: 03/02/2021] [Indexed: 11/17/2022] Open
Abstract
The recently identified nonsymbiotic hemoglobin gene MtGlb1-2 of the legume Medicago truncatula possesses unique properties as it generates four alternative splice forms encoding proteins with one or two heme domains. Here we investigate the ligand binding kinetics of MtGlb1-2.1 and MtGlb1-2.4, bearing two hemes and one heme, respectively. Unexpectedly, the overall time-course of ligand rebinding was unusually fast. Thus, we complemented nanosecond laser flash photolysis kinetics with data collected with a hybrid femtosecond–nanosecond pump–probe setup. Most photodissociated ligands are rebound geminately within a few nanoseconds, which leads to rates of the bimolecular rebinding to pentacoordinate species in the 108 M−1s−1 range. Binding of the distal histidine to the heme competes with CO rebinding with extremely high rates (kh ~ 105 s−1). Histidine dissociation from the heme occurs with comparable rates, thus resulting in moderate equilibrium binding constants (KH ~ 1). The rate constants for ligation and deligation of distal histidine to the heme are the highest reported for any plant or vertebrate globin. The combination of microscopic rates results in unusually high overall ligand binding rate constants, a fact that contributes to explaining at the mechanistic level the extremely high reactivity of these proteins toward the physiological ligands oxygen, nitric oxide and nitrite.
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Rong JC, Ji BW, Zheng N, Sun ZZ, Li YS, Xie BB. Genomic insights into antioxidant activities of Pyruvatibacter mobilis CGMCC 1.15125 T, a pyruvate-requiring bacterium isolated from the marine microalgae culture. Mar Genomics 2020; 55:100791. [PMID: 33517978 DOI: 10.1016/j.margen.2020.100791] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/04/2020] [Accepted: 06/08/2020] [Indexed: 11/19/2022]
Abstract
Pyruvate is a well-known scavenger of reactive oxygen species (ROS) like hydrogen peroxide and could prevent cells from oxidative damage. A pyruvate-requiring marine bacterium, Pyruvatibacter mobilis CGMCC 1.15125T (=KCTC 42509T), was isolated from the culture broth of a photosynthetic marine microalga. Here we report the complete genome sequence of Pyruvatibacter mobilis, which contained a circular chromosome of 3,333,914 bp with a mean G + C content of 63.9%. Through genomic analysis, we revealed that strain CGMCC 1.15125T encodes genes for some antioxidants like superoxide dismutase, glutathione, rubrerythrin and globin to relieve cellular oxidative stress, while pyruvate added to the medium may reduce extracellular ROS. The genome features of P. mobilis provide further insights into the antioxidant activities of bacteria surviving in oxygen-enriched habitats.
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Affiliation(s)
- Jin-Cheng Rong
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Bo-Wen Ji
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Ning Zheng
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Zhong-Zhi Sun
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yi-Song Li
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Bin-Bin Xie
- Microbial Technology Institute and State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China.
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