Enhancing boll protein synthesis and carbohydrate conversion by the application of exogenous amino acids at the peak flowering stage increased the boll Bt toxin concentration and lint yield in cotton

In Bacillus thuringenesis(Bt) transgenic cotton, the cotton boll has the lowest insecticidal protein content when compared to the other organs. The present study investigated the effects of amino acid spray application at the peak flowering stage on the cotton boll Bt toxin concentration and yield formation. Boll protein synthesis and carbohydrate conversion were also studied to reveal the fundamental mechanism. Three treatments(i.e., CK, the untreated control;LA1, five amino acids;LA2, 21 amino acids) were applied to two Bt cultivars of G. hirsutum(i.e., the hybrid Sikang 3 and the conventional Sikang 1) in the cotton-growing seasons during 2017 and 2018. Amino acid spray application at the peak flowering stage resulted in an increase of 5.2–16.4% in the boll Bt protein concentration and an increase of 5.5–11.3%in the seed cotton yield, but there was no difference between the two amino acid treatments. In addition, amino acid applications led to increases in the amino acid content, soluble protein content, glutamate pyruvate transaminase(GPT)activity, glutamate oxaloacetate transaminase(GOT) activity, glucose content, fructose content and soluble acid invertase(SAI) activity. This study also found that Bt protein content, enhanced boll number and the weight of opened bolls were closely related to carbon and nitrogen metabolism. The Bt protein content had significant linear positive correlations with amino acid and soluble protein contents. Enhanced boll number had significant linear positive correlations with the GPT and GOT activities from 15–25 days after flowering(DAF). The weight of opened bolls from 55–65 DAF had a significant linear positive correlation with the SAI activity. These results indicate that the enhancement of boll protein synthesis and carbohydrate conversion by amino acid application resulted in a simultaneous increase in the boll Bt protein concentration and cotton lint yield.

RESPONSES TO ETHYLENE AND PROTEIN SYNTHESIS OF CARNATION FLOWERS

The symptoms of petal response to ethylene, including petal in-rolling and increase in ion leakage through cell membrane, were completely inhibited by treatment of transcription inhibitor a-amanitin as well as protein synthesis inhibitor--cycloheximide. It was observed in Dianthus caryophyllus L. cv. White Sim that protein synthesis in flowers declined and the responsiveness to ethylene increased as the flowers became matured. However, when the flowers were pre-treated with aminooxyacetic acid (AOA), an inhibitor of ethylene synthesis, the observed responsiveness to ethylene in flowers declined with age. These results suggested that responsiveness to ethylene in flowers may be due to a declination in the capacity of protein synthesis in flowers.

Leucine Supplementation in a Chronically Protein-Restricted Diet Enhances Muscle Weight and Postprandial Protein Synthesis of Skeletal Muscle by Promoting the mTOR Pathway in Adult Rats

Low protein intake causes a decrease in protein deposition in most animal tissues. The purpose of this study was to investigate whether leucine supplementation would increase the synthesis rate of protein and muscle weight in adult rats, which chronically consume only 58.8% of their protein requirements. Thirty-six male Sprague-Dawley rats were assigned to one of three dietary treatments including a 20% casein diet （CON）, a 10% casein ＋ 0.44% alanine diet （R）, and a 10% casein ＋ 0.87% leucine diet （RL）. After a 10 d dietary treatment, plasma amino acid levels were measured after feeding, the gastrocnemius muscles and soleus muscles were harvested and weighed, and the fractional synthesis rate （FSR） and mammalian target of rapamycin （mTOR） signaling proteins in skeletal muscle were measured. Regarding the plasma amino acid level, the RL group had the highest concentration of leucine （P 〈 0.05） and the lowest concentration of isoleucine （P 〈 0.05） among the three groups, and the CON group had a lower concentration of valine （P 〈 0.05） than the R and RL groups. Compared with the R and RE groups, the CON group diet significantly increased （P 〈 0.05） feed intake, protein synthesis rate, and the phosphorylation of eukaryutic initiation factor 4E binding protein 1 （4E-BP1）, and decreased the weight of abdominal adipose. Compared with the R group, the RL group significantly increased in gastrocnemius muscle weight, protein synthesis rate, and phosphorylation of both ribosomal protein $6 kinase 1 （56K1） and 4E-BP1. In conclusion, when protein is chronically restricted in adult rat diets, leucine supplementation moderately improves body weight gain and increases muscle protein synthesis through mTOR activation,

Protein synthesis modulation as a therapeutic approach for amyotrophic lateral sclerosis and frontotemporal dementia

Protein synthesis is essential for cells to perform life metabolic processes.Pathological alterations of protein content can lead to particular diseases.Cells have an intrinsic array of mechanisms and pathways that are activated when protein misfolding,accumulation,aggregation or mislocalization occur.Some of them(like the unfolded protein response)represent complex interactions between endoplasmic reticulum sensors and elongation factors that tend to increase expression of chaperone proteins and/or repress translation in order to restore protein homeostasis(also known as proteostasis).This is even more important in neurons,as they are very susceptible to harmful effects associated with protein overload and proteostatic mechanisms are less effective with age.Several neurodegenerative pathologies such as Alzheimer’s,Parkinson’s,and Huntington’s diseases,amyotrophic lateral sclerosis and frontotemporal dementia exhibit a particular molecular signature of distinct,unbalanced protein overload.In amyotrophic lateral sclerosis and frontotemporal dementia,the majority of cases present intracellular inclusions of ubiquitinated transactive response DNA-binding protein of 43 kDa(TDP-43).TDP-43 is an RNA binding protein that participates in RNA metabolism,among other functions.Dysregulation of TDP-43(e.g.aggregation and mislocalization)can dramatically affect neurons,and this has been linked to disease development.Expression of amyotrophic lateral sclerosis/frontotemporal dementia TDP-43-related mutations in cellular and animal models has been shown to recapitulate key features of the amyotrophic lateral sclerosis/frontotemporal dementia disease spectrum.These variants can be causative of degeneration onset and progression.Most neurodegenerative diseases(including amyotrophic lateral sclerosis and frontotemporal dementia)have no cure at the moment;however,modulating translation has recently emerged as an attractive approach that can be performed at several steps(i.e.regulating activation of initiation and elongation factors,inhibiting unfolded protein response activation or inducing chaperone expression and activity).This review focuses on the features of protein imbalance in neurodegenerative disorders and the relevance of developing therapeutical compounds aiming at restoring proteostasis.We strive to highlight the importance of research on drugs that,not only restore protein imbalance without compromising translational activity of cells,but are also as safe as possible for the patients.

RNA and Protein Requirements for Eukaryotic Selenoprotein Synthesis

Selenium has been recognized as an essential nutrient in animals since the 1950s. Demonstration of the role of dietary selenium in protection from oxidative stress foIlowed in the early 1970s, and was largely attributed to its presence as an integral part of cellular glutathione peroxidase. However, the functions of this enzyme did not explain many of the other effects of selenium deficiency. The identification of other mammalian selenoproteins during the last few years has provided new insights into the functions of this trace nutrient. The discovery that type 1 deiodinase (D1) is a selenoenzyme, in addition to unveiling an essential role for selenium in thyroid hormone action, has had more far-reaching implications. Studies of this protein opened the door for investigation of the requirements for eukaryotic selenoprotein synthesis,and the features that distinguish this pathway from the corresponding prokaryotic pathway.Selenium is present in a number of prokaryotic and eukaryotic proteins in the form of the unusual amino acid, selenocysteine. Incorporation of selenocysteine into these proteins requires a novel translation step in which UGA specifies selenocysteine insertion. Since UGA codons are typically recognized as translation stop signals, an intriguing question is raised: How does a cell recognize and distinguish a UGA selenocysteine codon from a UGA stop codon? In this review, we will focus on what is known about selenocysteine incorporation in eukaryotes, briefly summarizing initial studies and discussing a few recent advances in our understanding of this unique 'recoding' process

Potential Genes for Regulation of Milk Protein Synthesis in Dairy Goat Mammary Gland

The lactating mammary gland is a prodigious protein-producing factory, but the milk protein synthesis mechanisms are not well understood. The major objective of this paper was to elucidate which genes and pathways were involved in the regulation of milk protein synthesis in the dairy goat mammary gland. Total 36 primiparous Guanzhong dairy goats were allotted in 12 groups according to their mammary development stages： days 90 and 150 of virgin, days 30, 90, and 150 of pregnancy, days 1, 10, 35, and 60 of lactation and days 3, 7, and 21 of involution （three animals per group）. Mammary tissue RNA was isolated for quantitative real- time RT-PCR of four casein genes alpha-s 1 casein （CSN 1S 1 ）, alpha-s2 casein （CSN 1 S2）, beta-casein （CSN2） and casein kappa （CSN3）, four whey protein genes lactoglobulin （LGB）, laetalbumin （LALBA）, laetofarrin （LTF）, and Whey acidic protein （WAP） and the genes which were potentially to regulate dairy goat milk protein synthesis at the level of transcription or translation [prolactin receptor （PRLR）, AKT1, signal transducers and activators of transcription 5 （STAT5）, E74-Like Factor 5 （ELF5）, eukaryotic translation initiation factor 4E binding protein 1 （EIF4E-BP1）, S6kinase （S6K） and caveolin 1]. The results showed that all genes were up-regulated in lactation period. The expressions of PRLR, AKT1, STAT5, ELF5, and S6K were similar to mRNA expressions of milk proteins. Our results indicated that milk protein synthesis in dairy goat mammary gland was possibly regulated by these genes.

REVERSAL OF THE DOUBLE-STRANDED-RNA-INDUCED INHIBITION OF PROTEIN SYNTHESIS BY A CATALYTICALLY INACTIVE MUTANT OF THE PROTEIN KINASE PKR

The interferon-inducible-stranded-RNA-depedet protein kinase PKR has been implicated in both the antiviral aand cell growth-regulatory effects of the interferons.Over-expression of the wild-type form of this protein inhibits cell proliferation,whereas over-expression of inactive mutant forms transforms cells to a tumouri-genie phenotype.It has been suggested that mutant PKR exerts a dominant negative effect on the activity of the wild-type protein kinase.We have investigated this possibility using the rabbbit reticulocyte cell-free translation system in which protein synthesis is inhibited by dsRNA due to activation of PKR and phosphorylation of initiation factor elF-2. Addition of a highly purified inactive PKR mutant,synthesised in a baculovirus-infected insect cell system, rescues protein synthesis from inhibition by the low concentrations of dsRNA in a dose-dependent manner. The PKR mutant has no effect on protein synthesis in the absence of dsRNA of in the presence of another inhibitory protein kinase,the haem-controlled repressor.Inhibition of translation can be re-established in the presence of the mutant PKR by adding a higher concentration of dsRNA.These results suggest that inactive mutant PKR does exert a dominant negative effect on wild-type PKR and that this may be due to competition for dsRNA binding.

Effect of Chronic Supplementation with L-Arginine on the Expression of Proteins that Regulate Muscle Protein Synthesis in Rats Trained in High-Intensity Exercise

Arginine is a conditionally essential amino acid that has been correlated with muscle protein synthesis. In order to investigate the effect of chronic supplementation of L-arginine on muscle protein synthesis via mTOR （mammalian target of rapamycin）, and contribute to the new scientific discussions on this amino acid in this context, adult male Wistar rats weighing about 200 g each were used, divided into four groups： TA （trained arginine）, SA （sedentary arginine）, CT （diet-control trained）, and CS （diet-control sedentary）. The diets were based on proposal A1N-93 （American Institute of Nutrition-1993）, in which one of them was enriched with 2% of arginine and the other with a mix of nonessential amino acids. Training of the animals consisted of sessions composed of four series of 10 jumps in a tank of water. Jumps were performed with a load of 50% of animals＇ body weight, five days a week for six weeks. Blood analyses done were insulin, glucose, amino acids, IGF-1 （insulin-like growth factor 1）, 1GFBP-3 （insulin-like growth factor-binding protein 3）, urea, and creatinine, as well as muscle and liver IGF-1. Molecular analyses were for IRS-1 （insulin receptor substrate 1）, PKB （protein kinase B）, also known as Akt, roTOR, 4E-BP1 （eukaryotic initiation factor 4E-binding protein 1） and p70S6K （p70 S6 kinase） by Western Blotting method. As a result, no statistically significant differences were found in the parameters evaluated except for creatinine, which was higher for the groups supplemented with arginine.

The Effect of Human Recombinant Interferon Gamma(hrIFN-γ)on hCG Secretion of Trophoblast and Protein Synthesis of Decidual Tissue in Vitro

In this study the effect of human recombinant interferon gamma hrIFN-γ)on hCG secretion of human first trimester trophoblast and protein synthesis of decidual tissue was investigated in vitro.The results indicated that hrIFN-γat the doses of 250 U/ml medium and 2500 U/ml medium decreased hCG secretion of trophoblast obviously(P<0.05, P<0.01)in a dose dependent manner.The effect of hrIFN-γon protein synthesis at the doses of 10 U to 1,000 U/ml medium inhibited the 3H leucine incorporation obviously.The cpm values between control and experimental groups were significantly different(P<0. 05) in a dosedependent manner.Furthermore its inhibitory effect is in a dose-dependent manner and was neutralized by IFN-γantiserum.The IFN-a at the doses used did not find any effect on protein synthesis in decidual tissue.

Influence of sodium fluoride on alkaline phosphatase activity and bone gla protein synthesis in human yellow ligament cells in vitro

Objective To investigate the influence of sodium fluoride(NaF)on alkaline phosphatase(ALP)activity and bone gla protein(BGP)synthesis in yellow ligament cells from different surgical simples in vitro.Methods The human ligament cells

Recent advances in chemical protein synthesis:method developments and biological applications

The central dogma of modern biology underscores the pivotal roles proteins play in diverse biological processes,the study of which necessitates advanced methods to produce proteins with precision and versatility.Chemical protein synthesis,a powerful approach utilizing chemical reactions for the de novo construction of structurally accurate proteins,has emerged as a transformative tool for studying proteins and generating protein derivatives/mimics inaccessible by natural biological machinery,including post-translationally modified proteins,proteins comprised of unnatural amino acids,as well as mirror-image proteins.This review summarizes recent strides in synthetic method developments for chemical protein synthesis,including innovative techniques in solid-phase peptide synthesis,the challenges presented by difficult sequences in either synthesis or folding and the exploration of novel ligation reactions using both chemical and enzymatic methods.Furthermore,the review also delves into newly developed protocols for site-selective protein modifications and the generation of stapled or macrocyclized peptides/miniproteins,highlighting the power of chemical methods to make structurally diverse proteins.Recent applications of synthetic proteins in investigating post-translational modifications(phosphorylation,lipidation,glycosylation,ubiquitination,etc.),mirror-image biological processes and drug development are further discussed.Together,these topics provide a comprehensive overview of the current landscape of chemical protein synthesis.

An improved installation of 2-hydroxy-4-methoxybenzyl(iHmb)method for chemical protein synthesis

The 2-hydroxy-4-methoxybenzyl(Hmb)backbone modification can prevent amide bond-mediated sidereactions(e.g.,aspartimide formation,peptide aggregation)by installing the removable Hmb group into a peptide bond,thus improving the synthesis of long and challenging peptides and proteins.However,its use is largely precluded by the limited Hmb’s installation sites.In this report,an improved installation of Hmb(iHmb)method was developed to achieve the flexible installation and the convenient removal of Hmb.The iHmb method involves two critical steps:(1)oxidative diazotization of the readily installed 2-hydroxy-4-methoxy-5-amino-benzyl(Hmab)to give 2-hydroxy-4-methoxy-5-diazonium-benzyl(Hmdab)by combining soamyl nitrite(IAN)/HBF_(4),and(2)reductive elimination of Hmdab to give the desired Hmb by 1,2-ethanedithiol(EDT).The iHmb method enables the installation of Hmb at any primary amino acid including the highly sterically hindered amino acids(e.g.,valine and isoleucine).The practicality and utility of the iHmb method was demonstrated by one-shot solid-phase synthesis of a challenging aspartimide-prone peptide,the mirror-image version of a hydrophobic peptide and a long-chain peptide up to 76-residue.Furthermore,the iHmb method can be utilized to facilitate chemical protein ligation,as exemplified by the synthesis of the single-spanning membrane protein sarcolipin.The iHmb method expands the toolkit for peptide synthesis and ligation and facilitates the preparation of peptides/proteins.

Low rumen degradable starch promotes the growth performance of goats by increasing protein synthesis in skeletal muscle via the AMPK-mTOR pathway

Since starch digestion in the small intestine provides more energy than digestion in the rumen of ru-minants,reducing dietary rumen degradable starch(RDS)content is beneficial for improving energy utilization of starch in ruminants.The present study tested whether the reduction of rumen degradable starch by restricting dietary corn processing for growing goats could improve growth performance,and further investigated the possible underlying mechanism.In this study,twenty-four 12-wk-old goats were selected and randomly allocated to receive either a high RDS diet(HRDS,crushed corn-based concen-trate,the mean of particle sizes of corn grain=1.64 mm,n=12)or a low RDS diet(LRDS,non-processed corn-based concentrate,the mean of particle sizes of corn grain>8 mm,n=12).Growth performance,carcass traits,plasma biochemical indices,gene expression of glucose and amino acid transporters,and protein expression of the AMPK-mTOR pathway were measured.Compared to the HRDS,LRDS tended to increase the average daily gain(ADG,P=0.054)and decreased the feed-to-gain ratio(F/G,P<0.05).Furthermore,LRDS increased the net lean tissue rate(P<0.01),protein content(P<0.05)and total free amino acids(P<0.05)in the biceps femoris(BF)muscle of goats.LRDS increased the glucose concen-tration(P<0.01),but reduced total amino acid concentration(P<0.05)and tended to reduce blood urea nitrogen(BUN)concentration(P=0.062)in plasma of goats.The mRNA expression of insulin receptors(INSR),glucose transporter 4(GLUT4),L-type amino acid transporter 1(LAT1)and 4F2 heavy chain(4F2hc)in BF muscle,and sodium-glucose cotransporters 1(SGLT1)and glucose transporter 2(GLUT2)in the small intestine were significantly increased(P<0.05)in LRDS goats.LRDS also led to marked activation of p70-S6 kinase(S6K)(P<0.05),but lower activation of AMP-activated protein kinase(AMPK)(P<0.05)and eukaryotic initiation factor 2a(P<0.01).Our findings suggested that reducing the content of dietary RDS enhanced postruminal starch digestion and increased plasma glucose,thereby improving amino acid utilization and promoting protein synthesis in the skeletal muscle of goats via the AMPK-mTOR pathway.These changes may contribute to improvement in growth performance and carcass traits in LRDS goats.

Chemical protein synthesis elucidates key modulation mechanism of the tyrosine-O-sulfation in inducing strengthened inhibitory activity of hirudin

Tyrosine sulfation is an important post-translational modification that enhances the inhibitory activity of hirudin.Herein,we developed a facile synthetic strategy to afford the sulfated hirudins with up to three modifications and in multi-milligram scales,after a single HPLC purification step.Through these synthetic proteins,a novel type of modulation mechanism exhibited by tyrosine sulfation was proposed,which would help to delineate the structure-function relationships in other sulfated proteins and more importantly,to serve as a basis for the development of related antithrombotic agents.

Preliminary Isolation of Hormone Stimulating Muscle Protein Synthesis in Thoracic Ganglia from the Prawn, Macrobrachium rosenbergii

The results of the previous studies seem to show the crustaceans can secrete growth hormone,which regulate their growth.However,more evidences are needed to determine it.So the following research was conducted.The extract of thoracic ganglia (TGE) of adult Macrobrachium rosenbergii was applied to a Sephadex G-50 column,the resulting second peak was further isolated by HPLC,and 9 fractions were obtained.Among the fractions only the second fraction significantly increased the protein synthesis of the abdomen muscle of the juvenile M.rosenbergii that was injected TGE.The increasing effects were related to the protein concentration of the injecting fractions.The molecular weight of the substance in the second fraction isolated by HPLC was below 3.4?kDa.The results indicate that the thoracic ganglia of M.rosenbergii could secrete a peptide hormone,which stimulates the muscle protein synthesis of prawn,and the hormone might be the growth hormone of the prawn.

Cell-free protein synthesis enabled rapid prototyping for metabolic engineering and synthetic biology

Advances in metabolic engineering and synthetic biology have facilitated the manufacturing of many valuable-added compounds and commodity chemicals using microbial cell factories in the past decade.However,due to complexity of cellular metabolism,the optimization of metabolic pathways for maximal production represents a grand challenge and an unavoidable barrier for metabolic engineering.Recently,cell-free protein synthesis system(CFPS)has been emerging as an enabling alternative to address challenges in biomanufacturing.This review summarizes the recent progresses of CFPS in rapid prototyping of biosynthetic pathways and genetic circuits(biosensors)to speed up design-build-test(DBT)cycles of metabolic engineering and synthetic biology.

Yeast knockout library allows for efficient testing of genomic mutations for cell-free protein synthesis

Cell-free protein synthesis(CFPS)systems from crude lysates have benefitted from modifications to their enzyme composition.For example,functionally deleting enzymes in the source strain that are deleterious to CFPS can improve protein synthesis yields.However,making such modifications can take substantial time.As a proof-of-concept to accelerate prototyping capabilities,we assessed the feasibility of using the yeast knockout collection to identify negative effectors in a Saccharomyces cerevisiae CFPS platform.We analyzed extracts made from six deletion strains that targeted the single deletion of potentially negative effectors(e.g.,nucleases).We found a statistically significant increase in luciferase yields upon loss of function of GCN3,PEP4,PPT1,NGL3,and XRN1 with a maximum increase of over 6-fold as compared to the wild type.Our work has implications for yeast CFPS and for rapidly prototyping strains to enable cell-free synthetic biology applications.

Chemical protein synthesis-assisted high-throughput screening strategies for D-peptides in drug discovery

D-peptides are recognized as a new class of synthetic chemical drugs and they possess many interesting advantages such as high enzymatic stability,improved oral bioavailability,as well as high binding affinity and specificity.Recently,D-peptide drugs have been attracting increasing attention in both academic and industrial researches over recent years.One D-peptide etelcalcetide has even entered the market that targets the calcium(Ca2+)-sensing receptor(CaSR) to fight secondary hyperparathyroidism.Effective discovery and optimization of D-peptide ligands that can bind to various disease-related targets with high specificity and potency is of great importance for the development of D-peptide drugs.This review surveys the recent method development in this area especially the chemical protein synthesis-assisted high-throughput screening strategies for D-peptide ligands and their application in drug discovery.

Silk fibroin as an additive for cell-free protein synthesis

Cell-free systems contain many proteins and metabolites required for complex functions such as transcription and translation or multi-step metabolic conversions.Research into expanding the delivery of these systems by drying or by embedding into other materials is enabling new applications in sensing,point-of-need manufacturing,and responsive materials.Meanwhile,silk fibroin from the silk worm,Bombyx mori,has received attention as a protective additive for dried enzyme formulations and as a material to build biocompatible hydrogels for controlled localization or delivery of biomolecular cargoes.In this work,we explore the effects of silk fibroin as an additive in cell-free protein synthesis(CFPS)reactions.Impacts of silk fibroin on CFPS activity and stability after drying,as well as the potential for incorporation of CFPS into hydrogels of crosslinked silk fibroin are assessed.We find that simple addition of silk fibroin increased productivity of the CFPS reactions by up to 42%,which we attribute to macromolecular crowding effects.However,we did not find evidence that silk fibroin provides a protective effects after drying as previously described for purified enzymes.Further,the enzymatic crosslinking transformations of silk fibroin typically used to form hydrogels are inhibited in the presence of the CFPS reaction mixture.Crosslinking attempts did not impact CFPS activity,but did yield localized protein aggregates rather than a hydrogel.We discuss the mechanisms at play in these results and how the silk fibroin-CFPS system might be improved for the design of cell-free devices.

CO_(2)-elevated cell-free protein synthesis

Gases are the vital nutrition of all organisms as the precursor of metabolism pathways.As a potential biological process,protein synthesis is inevitably regulated by gas transport and utilization.However,the effect of carbon dioxide(CO_(2))present in many metabolic pathways on protein synthesis has not been studied well.In this work,carbon dioxide combined with oxygen was employed for cell-free protein synthesis(CFPS)in the tube-in-tube reactor with precise control of gas concentration.In this in vitro system,gases could directly affect the protein synthesis process without transmembrane transport.Varied concentrations of carbon dioxide(0-1%)and constant oxygen concentration(21%)were employed for CFPS to assess the effects.The cell-free reactions with 0.3%CO_(2) and 21%O_(2) showed the highest protein yields.The combined effect of CO_(2) and O_(2) also resulted in relatively high protein expression under high oxygen conditions(0.3%CO_(2) and 100%O_(2)).Moreover,metabolomics assays were performed to gain insight into metabolic changes,which showed that CO_(2) slightly improved energy metabolism and redox balance.In particular,the extra supplied CO_(2) activated the decarboxylating reactions and removed toxic metabolites to recover the protein synthesis activity.The exploration of CO_(2) on protein synthesis could provide guiding implications for basic studies and biomanufacturing.