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Marine Drugs Oct 2023Phycobiliproteins (PBPs) are natural water-soluble pigment proteins, which constitute light-collecting antennae, and function in algae photosynthesis, existing in... (Review)
Review
Phycobiliproteins (PBPs) are natural water-soluble pigment proteins, which constitute light-collecting antennae, and function in algae photosynthesis, existing in cyanobacteria, red algae, and cryptomonads. They are special pigment-protein complexes in algae with a unique structure and function. According to their spectral properties, PBPs can be mainly divided into three types: allophycocyanin, phycocyanin, and PE. At present, there are two main sources of PBPs: one is natural PBPs extracted from algae and the other way is recombinant PBPs which are produced in engineered microorganisms. The covalent connection between PBP and streptavidin was realized by gene fusion. The bridge cascade reaction not only improved the sensitivity of PBP as a fluorescent probe but also saved the preparation time of the probe, which expands the application range of PBPs as fluorescent probes. In addition to its function as a light-collecting antenna in photosynthesis, PBPs also have the functions of biological detection, ion detection, and fluorescence imaging. Notably, increasing studies have designed novel PBP-based far-red fluorescent proteins, which enable the tracking of gene expression and cell fate.
Topics: Phycobiliproteins; Fluorescent Dyes; Photosynthesis
PubMed: 37999396
DOI: 10.3390/md21110572 -
Biotechnology For Biofuels and... Nov 2023Phycobiliproteins (PBPs), one of the functional proteins from algae, are natural pigment-protein complex containing various amino acids and phycobilins. It has various... (Review)
Review
Phycobiliproteins (PBPs), one of the functional proteins from algae, are natural pigment-protein complex containing various amino acids and phycobilins. It has various activities, such as anti-inflammatory and antioxidant properties. And are potential for applications in food, cosmetics, and biomedicine. Improving their metabolic yield is of great interest. Microalgaes are one of the important sources of PBPs, with high growth rate and have the potential for large-scale production. The key to large-scale PBPs production depends on accumulation and recovery of massive productive alga in the upstream stage and the efficiency of microalgae cells breakup and extract PBPs in the downstream stage. Therefore, we reviewed the status quo in the research and development of PBPs production, summarized the advances in each stage and the feasibility of scaled-up production, and demonstrated challenges and future directions in this field.
PubMed: 37941077
DOI: 10.1186/s13068-023-02387-z -
International Journal of Molecular... Jun 2023The phycobilisome (PBS) is the major light-harvesting apparatus in cyanobacteria and red algae. It is a large multi-subunit protein complex of several megadaltons that... (Review)
Review
The phycobilisome (PBS) is the major light-harvesting apparatus in cyanobacteria and red algae. It is a large multi-subunit protein complex of several megadaltons that is found on the stromal side of thylakoid membranes in orderly arrays. Chromophore lyases catalyse the thioether bond between apoproteins and phycobilins of PBSs. Depending on the species, composition, spatial assembly, and, especially, the functional tuning of different phycobiliproteins mediated by linker proteins, PBSs can absorb light between 450 and 650 nm, making them efficient and versatile light-harvesting systems. However, basic research and technological innovations are needed, not only to understand their role in photosynthesis but also to realise the potential applications of PBSs. Crucial components including phycobiliproteins, phycobilins, and lyases together make the PBS an efficient light-harvesting system, and these provide a scheme to explore the heterologous synthesis of PBS. Focusing on these topics, this review describes the essential components needed for PBS assembly, the functional basis of PBS photosynthesis, and the applications of phycobiliproteins. Moreover, key technical challenges for heterologous biosynthesis of phycobiliproteins in chassis cells are discussed.
Topics: Phycobilisomes; Phycobilins; Phycobiliproteins; Photosynthesis; Rhodophyta
PubMed: 37298688
DOI: 10.3390/ijms24119733 -
Plant Science : An International... Nov 2023The phycobilisome antennas, which contain phycobilin pigments instead of chlorophyll, are crucial for the photosynthetic activity of Cyanidioschyzon merolae cells, which... (Review)
Review
The phycobilisome antennas, which contain phycobilin pigments instead of chlorophyll, are crucial for the photosynthetic activity of Cyanidioschyzon merolae cells, which thrive in an acidic and hot water environment. The accessible light intensity and quality, temperature, acidity, and other factors in this environment are quite different from those in the air available for terrestrial plants. Under these conditions, adaptation to the intensity and quality of light, as well as temperature, which are key factors in photosynthesis of higher plants, also affects this process in Cyanidioschyzon merolae cells. Adaptation to varying light conditions requires fast remodeling and re-tuning of their light-harvesting antennas (phycobilisomes) at multiple levels, from regulation of gene expression to structural reorganization of protein-pigment complexes. This review presents selected data on the structure of phycobilisomes, the genetic engineering of the constituent proteins, and the latest results and opinions on the adaptation of phycobilisomes to light intensity and quality, and temperature to photosynthetic activities. We pay special attention to the latest results of the C. merolae research.
PubMed: 37659734
DOI: 10.1016/j.plantsci.2023.111854 -
Frontiers in Microbiology 2023Cyanophages affect the abundance, diversity, metabolism, and evolution of picocyanobacteria in marine ecosystems. Here we report an estuarine phage, S-CREM2, which...
Cyanophages affect the abundance, diversity, metabolism, and evolution of picocyanobacteria in marine ecosystems. Here we report an estuarine phage, S-CREM2, which represents a novel viral genus and leads to the establishment of a new T4-like cyanophage clade named cluster C. S-CREM2 possesses the longest tail (~418 nm) among isolated cyanomyoviruses and encodes six tail-related proteins that are exclusively homologous to those predicted in the cluster C cyanophages. Furthermore, S-CREM2 may carry three regulatory proteins in the virion, which may play a crucial role in optimizing the host intracellular environment for viral replication at the initial stage of infection. The cluster C cyanophages lack auxiliary metabolic genes (AMGs) that are commonly found in cyanophages of the T4-like clusters A and B and encode unique AMGs like an S-type phycobilin lyase gene. A variation in the composition of tRNA and regulatory RNA genes was observed between the marine and freshwater phage strains in cluster C, reflecting their different modes of coping with hosts and habitats. The cluster C cyanophages are widespread in estuarine and coastal regions and exhibit equivalent or even higher relative abundance compared to those of clusters A and B cyanophages in certain estuarine regions. The isolation of cyanophage S-CREM2 provides new insights into the phage-host interactions mediated by both newly discovered AMGs and virion-associated proteins and emphasizes the ecological significance of cluster C cyanophages in estuarine environments.
PubMed: 38029084
DOI: 10.3389/fmicb.2023.1293846 -
Communications Biology Sep 2023The mechanisms of acclimating to a nitrogen-fluctuating environment are necessary for the survival of aquatic cyanobacteria in their natural habitats, but our...
The mechanisms of acclimating to a nitrogen-fluctuating environment are necessary for the survival of aquatic cyanobacteria in their natural habitats, but our understanding is still far from complete. Here, the synthesis of phycobiliprotein is confirmed to be much earlier than that of photosystem components during recovery from nitrogen chlorosis and an unknown protein Ssr1698 is discovered to be involved in this synthetic process. The unknown protein is further identified as a c-type heme oxygenase (cHO) in tetrapyrrole biosynthetic pathway and catalyzes the opening of heme ring to form biliverdin IXα, which is required for phycobilin production and ensuing phycobiliprotein synthesis. In addition, the cHO-dependent phycobiliprotein is found to be vital for the growth of cyanobacterial cells during chlorosis and regreening through its nitrogen-storage and light-harvesting functions, respectively. Collectively, the cHO expressed preferentially during recovery from nitrogen chlorosis is identified in photosynthetic organisms and the dual function of this enzyme-dependent phycobiliprotein is proposed to be an important mechanism for acclimation of aquatic cyanobacteria to a nitrogen-fluctuating environment.
Topics: Humans; Heme Oxygenase (Decyclizing); Cyanobacteria; Acclimatization; Anemia, Hypochromic; Nitrogen; Phycobiliproteins
PubMed: 37714932
DOI: 10.1038/s42003-023-05315-x -
Biomolecules Mar 2024Phycocyanobilin (PCB) is a natural blue tetrapyrrole chromophore that is found in phycocyanin and plays an essential role in photosynthesis. Due to PCB's antioxidation,...
Phycocyanobilin (PCB) is a natural blue tetrapyrrole chromophore that is found in phycocyanin and plays an essential role in photosynthesis. Due to PCB's antioxidation, anti-inflammatory and anti-cancer properties, it has been utilized in the food, pharmaceutical and cosmetic industries. Currently, the extraction of PCB from involves complex processes, which has led to increasing interest in the biosynthesis of PCB in . However, the PCB titer remains low because of the poor activity of key enzymes and the insufficient precursor supply. Here, the synthesis of PCB was firstly improved by screening the optimal heme oxygenase (HO) from BP-1(HO) and PCB: ferredoxin oxidoreductase from sp. PCC6803 (PcyA). In addition, based on a rational design and the infrared fluorescence method for high-throughput screening, the mutants of HO(F29W/K166D) and PcyA(D220G/H74M) with significantly higher activities were obtained. Furthermore, a DNA scaffold was applied in the assembly of HO and PcyA mutants to reduce the spatial barriers, and the heme supply was enhanced via the moderate overexpression of and , resulting in the highest PCB titer (184.20 mg/L) obtained in a 5 L fermenter. The strategies applied in this study lay the foundation for the industrial production of PCB and its heme derivatives.
Topics: Phycocyanin; Escherichia coli; Phycobilins; Heme Oxygenase (Decyclizing); Heme
PubMed: 38540721
DOI: 10.3390/biom14030301