Selenaminosäuren: Die geschätzten "Selen"-Edelsteinchen der Biowissenschaften

Selenaminosäuren: Die geschätzten "Selen"-Edelsteinchen der Biowissenschaften

Selenoamino acids are unique selenium-containing organic molecules in living organisms, attracting sustained scientific interest due to their remarkable biological functions and broad application potential. Formed through chalcogen element substitution, they retain the fundamental properties of amino acids while conferring special physiological activities to organisms. Two main types are currently known: selenocysteine (Sec) and selenomethionine (SeMet). Together, they constitute the core carriers for biological selenium utilization, serving as a key bridge connecting inorganic selenium to life processes.

     I.The Two Selenium Heroes in the Code of Life

Selenocysteine is acclaimed as the “21st proteinogenic amino acid,” with its structure resolved in 1986. It is incorporated into proteins through a UGA stop codon recoding mechanism and acts as the catalytic center in antioxidant enzymes like glutathione peroxidase. Its characteristic selenol group (-SeH) exhibits stronger nucleophilicity and redox activity compared to the thiol group (-SH) in ordinary cysteine, enhancing free radical scavenging rates approximately 100-fold.

Selenomethionine is the selenium analog of methionine, naturally synthesized in plants and microorganisms, while animals require dietary intake. It can be non-specifically incorporated into proteins, forming long-term selenium storage pools. Studies show its half-life in animal muscle tissue reaches 20–30 days, with bioavailability significantly higher than inorganic selenium.

The two operate through precise collaborative mechanisms: Selenocysteine is transported by specific tRNA (tRNA^[Ser]Sec) and synthesized via multi-enzyme catalysis; selenomethionine enters cells through the methionine transport system and participates in the methyl cycle. This division of labor enables precise regulation and efficient utilization of selenium within organisms.

      II.Multidimensional Physiological Function Profiles

The antioxidant defense system establishes a three-tier mechanism: The GPx enzyme family clears peroxides, with GPx4 inhibiting lipid peroxidation by over 98%; thioredoxin reductase (TrxR) repairs oxidatively damaged proteins; enzymes like formate dehydrogenase maintain cellular redox homeostasis, forming a comprehensive protection network.

Immune regulation demonstrates bidirectional control: Selenoamino acids can enhance innate immunity while promoting regulatory T cell differentiation to maintain immune tolerance. In HPV infection experiments, selenocysteine reduced viral load by 2–3 orders of magnitude, activated the p53 pathway, and degraded viral proteins, demonstrating antiviral potential.

For heavy metal detoxification, their selenol groups can form stable Se-M complexes with mercury, lead, etc., with binding constants 3–5 orders of magnitude higher than ordinary thiol compounds. In a lead exposure model, selenomethionine reduced kidney lead accumulation by 76% and promoted excretion via ABC transporters.

      III. From Laboratory to Practical Applications

In nutritional fortification, selenomethionine is included in food safety standards, and selenocysteine is an ideal selenium supplement due to its high absorption rate. Clinically, its absorption is 40% higher than sodium selenite, maintains blood selenium levels twice as long, and can reduce glycated hemoglobin (HbA1c) by 1.5–2% in diabetic patients.

In agriculture and aquaculture, adding 0.3 mg/kg selenomethionine increased breeder duck fertility by 8.7% and reduced embryo mortality by 34%; in goat trials, muscle selenium deposition increased fivefold with significantly improved meat tenderness.

In pharmaceutical R&D, nano-drugs modified with selenoamino acids show 3–5 times higher tumor accumulation efficiency; selenocysteine analogs can modulate GABAergic neurons, reducing seizure frequency by 60–70%, offering new pathways for treating neurological diseases.

      IV.Future Prospects

Selenoamino acid research has entered a multidisciplinary era. Single-molecule imaging enables dynamic observation of selenol groups, and synthetic biology facilitates the reconstruction of biological pathways, advancing personalized medicine.

Against the backdrop of industry-academia-research integration, enterprises with independent R&D and production capabilities are key to translating achievements. For example, Changsha Yuteng New Material Co., Ltd., with its own factory and professional R&D team, is dedicated to developing and applying related technologies. For cooperation needs, please feel free to contact us to jointly explore the innovative prospects of selenoamino acids.

Changsha YuTeng New Materials Co, Ltd.

长沙钰腾新材料有限公司

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