Structural and functional characterization of peste des petits ruminants virus coded hemagglutinin protein using various in-silico approaches.

Peste des petits ruminants (PPR), a disease of socioeconomic importance has been a serious threat to small ruminants. The causative agent of this disease is PPR virus (PPRV) which belongs to the genus Morbillivirus. Hemagglutinin (H) is a PPRV coded transmembrane protein embedded in the viral envelope and plays a vital role in mediating the entry of virion particle into the cell. The infected host mounts an effective humoral response against H protein which is important for host to overcome the infection. In the present study, we have investigated structural, physiological and functional properties of hemagglutinin protein using various computational tools. The sequence analysis and structure prediction analysis show that hemagglutinin protein comprises of beta sheets as the predominant secondary structure, and may lack neuraminidase activity. PPRV-H consists of several important domains and motifs that form an essential scaffold which impart various critical roles to the protein. Comparative modeling predicted the protein to exist as a homo-tetramer that binds to its cognate cellular receptors. Certain amino acid substitutions identified by multiple sequence alignment were found to alter the predicted structure of the protein. PPRV-H through its predicted interaction with TLR-2 molecule may drive the expression of CD150 which could further propagate the virus into the host. Together, our study provides new insights into PPRV-H protein structure and its predicted functions.

Protein and amino acid digestibility: definitions and conventional oro-ileal determination in humans.

When assessing protein quality, a correction needs to be made to take into consideration the availability of the amino acids. This correction is based on the digestibility of the amino acids. It is recommended to use ileal (end of small intestine) digestibility as opposed to faecal digestibility. A correction needs to be made for endogenous (gut sourced as opposed to diet sourced) amino acids to give true digestibility as opposed to apparent digestibility. Also, this correction should be made by correcting the amino acid composition for individual amino acid digestibilities as opposed to correcting all amino acids for nitrogen digestibility. Determination of true ileal amino acid digestibility requires the collection of ileal digesta. In the human there are two methods that can be used; naso-ileal intubation and using the ileostomy model. Both are discussed in detail and it is concluded that both are appropriate methods to collect ileal digesta.

Serum amino acid profiles in clinically normal Noma horses.

Plasma or serum amino acids are used to evaluate nutritional status and metabolic disorders. In this study, we aimed to set reference values of serum amino acid concentrations in the Noma horse, a Japanese native horse. Thirty-one horses were classified into six age groups: neonatal foal (0-4 days), foal (0.5-1 years), youth (5 years), middle age (10 years), old (15 years), and extra-old (>20 years). Horses >5 years of age were analyzed together as the adult group. In the adult horses, there were no significant differences among the serum amino acid concentrations of each age group. The foal group had higher concentrations of alanine, aspartic acid, glutamic acid, α-aminoadipic acid, and 3-methyl-histidine than the adult group. The neonatal foal group had higher serum concentrations of phenylalanine, lysine, alanine, proline, aspartic acid, glutamic acid, ß-alanine, and ß-amino-iso-butyric acid and lower tryptophan concentrations and Fischer's ratios than the adult group. The neonatal foal group had higher ß-amino-iso-butyric acid concentrations and lower tryptophan and 3-methyl-histidine concentrations than the foal group. Therefore, reference values might be set separately in neonatal foals, foals, and adult horses. The data for the serum amino acid concentrations can be used for health care through physiological and pathological evaluations in Noma horses.

Utilizing codon degeneracy in the design of donor DNA for CRISPR/Cas9-mediated gene editing to streamline the screening process for single amino acid mutations.

Chlamydomonas reinhardtii, a unicellular green alga, has been widely used as a model organism for studies of algal, plant and ciliary biology. The generation of targeted amino acid mutations is often necessary, and this can be achieved using CRISPR/Cas9 induced homology-directed repair to install genomic modifications from exogenous donor DNA. Due to the low gene editing efficiency, the technical challenge lies in identifying the mutant cells. Direct sequencing is not practical, and pre-screening is required. Here, we report a strategy for generating and screening for amino acid point mutations using the CRISPR/Cas9 gene editing system. The strategy is based on designing donor DNA using codon degeneracy, which enables the design of specific primers to facilitate mutant screening by PCR. An in vitro assembled RNP complex, along with a dsDNA donor and an antibiotic resistance marker, was electroporated into wild-type cells, followed by PCR screening. To demonstrate this principle, we have generated the E102K mutation in centrin and the K40R mutation in α-tubulin. The editing efficiencies at the target sites for Centrin, TUA1, TUA2 were 4, 24 and 8% respectively, based on PCR screening. More than 80% of the mutants with the expected size of PCR products were precisely edited, as revealed by DNA sequencing. Subsequently, the precision-edited mutants were biochemically verified. The introduction of codon degeneracy did not affect the gene expression of centrin and α-tubulins. Thus, this approach can be used to facilitate the identification of point mutations, especially in genes with low editing rates.

Ectoine maintains the flavor and nutritional quality of broccoli during postharvest storage.

The bacterial derived osmolyte ectoine has been shown to stabilize cell structure and function, a property that may help to extend the shelf life of broccoli. The impact of ectoine on broccoli stored for 4 d at 20 °C and 90% relative humidity was investigated. Results indicated that 0.20% ectoine treatment maintained the quality of broccoli, by reducing rate of respiration and ethylene generation, while increasing the levels of total phenolics, flavonoids, TSS, soluble protein, and vitamin C, relative to control. Headspace-gas chromatography-mass spectrometry, transcriptomic and metabolomic analyses revealed that ectoine stabilized aroma components in broccoli by maintaining level of volatile compounds and altered the expression of genes and metabolites associated with sulfur metabolism, as well as fatty acid and amino acid biosynthesis pathways. These findings provide a greater insight into how ectoine preserves the flavor and nutritional quality of broccoli, thus, extending its shelf life.

Rapid in situ identification of honey authenticity based on RP-Nano-ESI-MS using online desalting.

High-content sugar in honey frequently results in severe matrix effects and requires complex pretreatment prior to analysis, posing significant challenges for the rapid analysis of honey. In this study, the reversal polarity nano-electrospray ionization mass spectrometry (RP-Nano-ESI-MS) analysis was developed for the direct evaluation of honey samples. The results indicated that RP-Nano-ESI-MS significantly mitigated the matrix effects induced by high-content sugar through the implementation of online desalting. Furthermore, RP-Nano-ESI-MS has been proven capable of not only differentiating acacia honey adulterated with 10% rape honey, but also effectively distinguishing six types of honey and exhibiting remarkable proficiency in detecting honey adulteration and botanical traceability. Additionally, RP-Nano-ESI-MS exhibited strong quantitative abilities, effectively characterizing variations in amino acid composition among six types of honey with high stability and reproducibility. Our studies underscore the significant potential of RP-Nano-ESI-MS for its rapid in situ analysis of sugar-rich foods like honey, especially in their authenticity verification.

Therapeutic implications of the metabolic changes associated with BRAF inhibition in melanoma.

Melanoma metabolism can be reprogrammed by activating BRAF mutations. These mutations are present in up to 50% of cutaneous melanomas, with the most common being V600E. BRAF mutations augment glycolysis to promote macromolecular synthesis and proliferation. Prior to the development of targeted anti-BRAF therapies, these mutations were associated with accelerated clinical disease in the metastatic setting. Combination BRAF and MEK inhibition is a first line treatment option for locally advanced or metastatic melanoma harboring targetable BRAF mutations. This therapy shows excellent response rates but these responses are not durable, with almost all patients developing resistance. When BRAF mutated melanoma cells are inhibited with targeted therapies the metabolism of those cells also changes. These cells rely less on glycolysis for energy production, and instead shift to a mitochondrial phenotype with upregulated TCA cycle activity and oxidative phosphorylation. An increased dependence on glutamine utilization is exhibited to support TCA cycle substrates in this metabolic rewiring of BRAF mutated melanoma. Herein we describe the relevant core metabolic pathways modulated by BRAF inhibition. These adaptive pathways represent vulnerabilities that could be targeted to overcome resistance to BRAF inhibitors. This review evaluates current and future therapeutic strategies that target metabolic reprogramming in melanoma cells, particularly in response to BRAF inhibition.

Symptoms and management of cow's milk allergy: perception and evidence.

Introduction: The diagnosis and management of cow's milk allergy (CMA) is a topic of debate and controversy. Our aim was to compare the opinions of expert groups from the Middle East (n = 14) and the European Society of Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) (n = 13). Methods: These Expert groups voted on statements that were developed by the ESPGHAN group and published in a recent position paper. The voting outcome was compared. Results: Overall, there was consensus amongst both groups of experts. Experts agreed that symptoms of crying, irritability and colic, as single manifestation, are not suggestive of CMA. They agreed that amino-acid based formula (AAF) should be reserved for severe cases (e.g., malnutrition and anaphylaxis) and that there is insufficient evidence to recommend a step-down approach. There was no unanimous consensus on the statement that a cow's milk based extensively hydrolysed formula (eHF) should be the first choice as a diagnostic elimination diet in mild/moderate cases. Although the statements regarding the role for hydrolysed rice formula as a diagnostic and therapeutic elimination diet were accepted, 3/27 disagreed. The votes regarding soy formula highlight the differences in opinion in the role of soy protein in CMA dietary treatment. Generally, soy-based formula is seldom available in the Middle-East region. All ESPGHAN experts agreed that there is insufficient evidence that the addition of probiotics, prebiotics and synbiotics increase the efficacy of elimination diets regarding CMA symptoms (despite other benefits such as decrease of infections and antibiotic intake), whereas 3/14 of the Middle East group thought there was sufficient evidence. Discussion: Differences in voting are related to geographical, cultural and other conditions, such as cost and availability. This emphasizes the need to develop region-specific guidelines considering social and cultural conditions, and to perform further research in this area.

Versatile functionalization of Bifidobacteria-derived extracellular vesicles using amino acid metabolic labeling and click chemistry for immunotherapy.

Extracellular vesicles (EVs) are nanoparticles secreted by various organisms. Methods for modifying EVs functionally have garnered attention for developing EV-based therapeutic systems. However, most technologies used to integrate these functions are limited to mammalian-derived EVs and a promising modification method for bacteria-derived EVs has not yet been developed. In this study, we propose a novel method for the versatile functionalization of immunostimulatory probiotic Bifidobacteria-derived EVs (B-EVs) using amino acid metabolic labeling and azide-alkyne click reaction. Azide D-alanine (ADA), a similar molecule to D-alanine in bacteria cell-wall peptidoglycan, was selected as an azide group-functionalized amino acid. Azide-modified B-EVs were isolated from Bifidobacteria incubated with ADA. The physicochemical and compositional characteristics, as well as adjuvanticity of B-EVs against immune cells were not affected by azide loading, demonstrating that this functionalization approach can retain the endogenous usefulness of B-EVs. By using the fluorescent B-EVs obtained by this method, the intracellular trafficking of B-EVs after uptake by immune cells was successfully observed. Furthermore, this method enabled the formulation of B-EVs for hydrogelation and enhanced adjuvanticity in the host. Our findings will be helpful for further development of EV-based immunotherapy.

Characterisation of a microelectrochemical biosensor for real-time detection of brain extracellular d-serine.

A modified development protocol and concomitant characterisation of a first generation biosensor for the detection of brain extracellular d-serine is reported. Functional parameters important for neurochemical monitoring, including sensor sensitivity, O2 interference, selectivity, shelf-life and biocompatibility were examined. Construction and development involved the enzyme d-amino acid oxidase (DAAO), utilising a dip-coating immobilisation method employing a new extended drying approach. The resultant Pt-based polymer enzyme composite sensor achieved high sensitivity to d-serine (0.76 ± 0.04 nA mm-2. µM-1) and a low µM limit of detection (0.33 ± 0.02 µM). The in-vitro response time was within the solution stirring time, suggesting potential sub-second in-vivo response characteristics. Oxygen interference studies demonstrated a 1 % reduction in current at 50 µM O2 when compared to atmospheric O2 levels (200 µM), indicating that the sensor can be used for reliable neurochemical monitoring of d-serine, free from changes in current associated with physiological O2 fluctuations. Potential interference signals generated by the principal electroactive analytes present in the brain were minimised by using a permselective layer of poly(o-phenylenediamine), and although several d-amino acids are possible substrates for DAAO, their physiologically relevant signals were small relative to that for d-serine. Additionally, changing both temperature and pH over possible in vivo ranges (34-40 °C and 7.2-7.6 respectively) resulted in no significant effect on performance. Finally, the biosensor was implanted in the striatum of freely moving rats and used to monitor physiological changes in d-serine over a two-week period.

The effectiveness of selection in a species affects the direction of amino acid frequency evolution.

Nearly neutral theory predicts that species with higher effective population size (N e ) are better able to purge slightly deleterious mutations. We compare evolution in high-N e vs. low-N e vertebrates to reveal which amino acid frequencies are subject to subtle selective preferences. We take three complementary approaches, two measuring flux and one measuring outcomes. First, we fit non-stationary substitution models of amino acid flux using maximum likelihood, comparing the high-N e clade of rodents and lagomorphs to its low-N e sister clade of primates and colugos. Second, we compare evolutionary outcomes across a wider range of vertebrates, via correlations between amino acid frequencies and N e . Third, we dissect the details of flux in human, chimpanzee, mouse, and rat, as scored by parsimony - this also enables comparison to a historical paper. All three methods agree on which amino acids are preferred under more effective selection. Preferred amino acids tend to be smaller, less costly to synthesize, and to promote intrinsic structural disorder. Parsimony-induced bias in the historical study produces an apparent reduction in structural disorder, perhaps driven by slightly deleterious substitutions. Within highly exchangeable pairs of amino acids, arginine is strongly preferred over lysine, and valine over isoleucine, consistent with more effective selection preferring a marginally larger free energy of folding. These two preferences match differences between thermophiles and mesophilic relatives. These results reveal the biophysical consequences of mutation-selection-drift balance, and demonstrate the utility of nearly neutral theory for understanding protein evolution.

Amino acids regulating skeletal muscle metabolism: mechanisms of action, physical training dosage recommendations and adverse effects.

Maintaining skeletal muscle mass is important for improving muscle strength and function. Hence, maximizing lean body mass (LBM) is the primary goal for both elite athletes and fitness enthusiasts. The use of amino acids as dietary supplements is widespread among athletes and physically active individuals. Extensive literature analysis reveals that branched-chain amino acids (BCAA), creatine, glutamine and ß-alanine may be beneficial in regulating skeletal muscle metabolism, enhancing LBM and mitigating exercise-induced muscle damage. This review details the mechanisms of these amino acids, offering insights into their efficacy as supplements. Recommended dosage and potential side effects are then outlined to aid athletes in making informed choices and safeguard their health. Lastly, limitations within the current literature are addressed, highlighting opportunities for future research.

Comparative proteomics uncovers low asparagine content in Plasmodium tRip-KO proteins.

tRNAs are not only essential for decoding the genetic code, but their abundance also has a strong impact on the rate of protein production, folding, and on the stability of the translated messenger RNAs. Plasmodium expresses a unique surface protein called tRip, involved in the import of exogenous tRNAs into the parasite. Comparative proteomic analysis of the blood stage of wild-type and tRip-KO variant of P. berghei parasites revealed that downregulated proteins in the mutant parasite are distinguished by a bias in their asparagine content. Furthermore, the demonstration of the possibility of charging host tRNAs with Plasmodium aminoacyl-tRNA synthetases led us to propose that imported host tRNAs participate in parasite protein synthesis. These results also suggest a novel mechanism of translational control in which import of host tRNAs emerge as regulators of gene expression in the Plasmodium developmental cycle and pathogenesis, by enabling the synthesis of asparagine-rich regulatory proteins that efficiently and selectively control the parasite infectivity.

The duality of sulfate-reducing bacteria: Reducing methylmercury production in rhizosphere but enhancing accumulation in rice plants.

Sulfate-reducing bacteria (SRB) are known to alter methylmercury (MeHg) production in paddy soil, but the effect of SRB on MeHg dynamics in rhizosphere and rice plants remains to be fully elucidated. The present study investigated the impact of SRB on MeHg levels in unsterilized and γ-sterilized mercury-polluted paddy soils, with the aim to close this knowledge gap. Results showed that the presence of SRB reduced MeHg production by ∼22 % and ∼17 % in the two soils, but elevated MeHg contents by approximately 55 % and 99 % in rice grains, respectively. Similar trend at smaller scales were seen in roots and shoots. SRB inoculation exerted the most profound impact on amino acid metabolism in roots, with the relative response of L-arginine positively linking to MeHg concentrations in rhizosphere. The SRB-induced enrichment of MeHg in rice plants may be interpreted by the stronger presence of endophytic nitrogen-related microbes (e.g. Methylocaldum, Hyphomicrobium and Methylocystis) and TGA transcription factors interacting with glutathione metabolism and calmodulin. Our study provides valuable insights into the complex effects of SRB inoculation on MeHg dynamics in rice ecosystems, and may help to develop strategies to effectively control MeHg accumulation in rice grains.

A novel amino acid metabolism-related gene signature to predict the overall survival of esophageal squamous cell carcinoma patients.

Background: Esophageal squamous cell carcinoma (ESCC) has a poor early detection rate, prognosis, and survival rate. Effective prognostic markers are urgently needed to assist in the prediction of ESCC treatment outcomes. There is accumulating evidence of a strong relationship between cancer cell growth and amino acid metabolism. This study aims to determine the relationship between amino acid metabolism and ESCC prognosis. Methods: This study comprehensively evaluates the association between amino acid metabolism-related gene (AAMRG) expression profiles and the prognosis of ESCC patients based on data from The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) databases. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to verify the expression of prognosis-related genes. Results: A univariate Cox regression analysis of TCGA data identified 18 prognosis-related AAMRGs. The gene expression profiles of 90 ESCC tumor and normal tissues were obtained from the GSE20347 and GSE67269 datasets. Two differently expressed genes (DEGs) were considered as ESCC prognosis-related genes; and they were branched-chain amino acid transaminase 1 (BCAT1) and methylmalonic aciduria and homocystinuria type C protein (MMACHC). These two AAMRGs were used to develop a novel AAMRG-related gene signature to predict 1- and 2-year prognostic risk in ESCC patients. Both BCAT1 and MMACHC expression were verified by RT-qPCR. A prognostic nomogram that incorporated clinical factors and BCAT1 and MMACHC gene expression was constructed, and the calibration plots showed that it had good prognostic performance. Conclusions: The AAMRG signature established in our study is efficient and could be used in clinical settings to predict the early prognosis of ESCC patients.

Tuning tRNAs for improved translation.

Transfer RNAs have been extensively explored as the molecules that translate the genetic code into proteins. At this interface of genetics and biochemistry, tRNAs direct the efficiency of every major step of translation by interacting with a multitude of binding partners. However, due to the variability of tRNA sequences and the abundance of diverse post-transcriptional modifications, a guidebook linking tRNA sequences to specific translational outcomes has yet to be elucidated. Here, we review substantial efforts that have collectively uncovered tRNA engineering principles that can be used as a guide for the tuning of translation fidelity. These principles have allowed for the development of basic research, expansion of the genetic code with non-canonical amino acids, and tRNA therapeutics.

Varying the ratio of Lys: Met through enhancing methionine supplementation improved milk secretion ability through regulating the mRNA expression in bovine mammary epithelial cells under heat stress.

Introduction: The ratio of lysine (Lys) to methionine (Met) with 3.0: 1 is confirmed as the "ideal" profile for milk protein synthesis, but whether this ratio is suitable for milk protein synthesis under HS needs to be further studied. Methods: To evaluate the molecular mechanism by which HS and Lys to Met ratios affect mammary cell functional capacity, an immortalized bovine mammary epithelial cell line (MAC-T) is incubated with 5 doses of Met while maintaining a constant concentration of Lys. The MAC-T cells was treated for 6 h as follow: Lys: Met 3.0: 1 (control 37°C and IPAA 42°C) or treatments under HS (42°C) with different ratios of Lys: Met at 2.0: 1 (LM20), 2.5: 1 (LM25), 3.5: 1 (LM35) and 4.0: 1 (LM40). RNA sequencing was used to assess transcriptome-wide alterations in mRNA abundance. Results: The significant difference between control and other groups was observed base on PCA analysis. A total of 2048 differentially expressed genes (DEGs) were identified in the IPAA group relative to the control group. Similarly, 226, 306, 148, 157 DEGs were detected in the LM20, LM25, LM35 and LM40 groups, respectively, relative to the IPAA group. The relative mRNA abundance of HSPA1A was upregulated and anti-apoptotic genes (BCL2L1 and BCL2) was down-regulated in the IPAA group, compared to the control group (p < 0.05). Compared with the IPAA group, the relative mRNA abundance of anti-apoptotic genes and casein genes (CSN1S2 and CSN2) was up-regulated in the LM25 group (p < 0.05). The DEGs between LM25 and IPAA groups were associated with the negative regulation of transcription RNA polymerase II promoter in response to stress (GO: 0051085, DEGs of BAG3, DNAJB1, HSPA1A) as well as the mTOR signaling pathway (ko04150, DEGs of ATP6V1C2, WNT11, WNT3A, and WNT9A). Several DEGs involved in amino acids metabolism (AFMID, HYKK, NOS3, RIMKLB) and glycolysis/gluconeogenesis (AFMID and MGAT5B) were up-regulated while DEGs involved in lipolysis and beta-oxidation catabolic processes (ALOX12 and ALOX12B) were down-regulated. Conclusion: These results suggested that increasing Met supply (Lys: Met at 2.5: 1) may help mammary gland cells resist HS-induced cell damage, while possibly maintaining lactation capacity through regulation of gene expression.

Therapeutic effects of Lingguizhugan decoction in a rat model of high-fat diet-induced insulin resistance.

BACKGROUND: Lingguizhugan (LGZG) decoction is a widely used classic Chinese medicine formula that was recently shown to improve high-fat diet (HFD)-induced insulin resistance (IR) in animal studies. AIM: To assess the therapeutic effect of LGZG decoction on HFD-induced IR and explore the potential underlying mechanism. METHODS: To establish an IR rat model, a 12-wk HFD was administered, followed by a 4-wk treatment with LGZG. The determination of IR status was achieved through the use of biochemical tests and oral glucose tolerance tests. Using a targeted meta-bolomics platform to analyze changes in serum metabolites, quantitative real-time PCR (qRT-PCR) was used to assess the gene expression of the ribosomal protein S6 kinase beta 1 (S6K1). RESULTS: In IR rats, LGZG decreased body weight and indices of hepatic steatosis. It effectively controlled blood glucose and food intake while protecting islet cells. Metabolite analysis revealed significant differences between the HFD and HFD-LGZG groups. LGZG intervention reduced branched-chain amino acid levels. Levels of IR-related metabolites such as tryptophan, alanine, taurine, and asparagine decreased significantly. IR may be linked to amino acids due to the contemporaneous increase in S6K1 expression, as shown by qRT-PCR. CONCLUSIONS: Our study strongly suggests that LGZG decoction reduces HFD-induced IR. LGZG may activate S6K1 via metabolic pathways. These findings lay the groundwork for the potential of LGZG as an IR treatment.

Selector of Amino-Acid Scales Set.

Experimental and theoretical properties of amino acids as building blocks of peptides and proteins have been extensively researched. Each such method assigns a number to each amino acid, and one such assignment is called amino-acid scale. Their usage in bioinformatics to explain and predict behaviour of peptides and proteins is of essential value. The number of such scales is very large. There are more than a hundred scales related just to hydrophobicity. A large number of scales can be a computational burden for algorithms that try to define peptide descriptors combining several of these scales. Hence, it is of interest to construct a smaller, but still representative set of scales. Here, we present software that does this. We test it on the set of scales using a database constructed by Kawashima and collaborators and show that it is possible to significantly reduce the number of scales observed without losing much of the information. An algorithm is implemented in C#. As a result, we provide a smaller database that might be a very useful tool for the analyses and construction of new peptides. Another interesting application of this database would be to compare the artificial intelligence construction of peptides having as an input the complete Kawashima database and this reduced one. Obtaining in both cases similar results would give much credibility to the constructs of such AI algorithms.

N-Terminal Sequences of Signal Peptides Assuming Critical Roles in Expression of Heterologous Proteins in Bacillus subtilis.

The N-terminal sequences of proteins and their corresponding encoding sequences may play crucial roles in the heterologous expression. In this study, the secretory expression of alkaline pectin lyase APL in B. subtilis was investigated to explore the effects of the N-terminal 5-7 amino acid sequences of different signal peptides on the protein expression and secretion. It was identified for the first time that the first five amino acid sequences of the N-terminal of the signal peptide (SP-LipA) from Bacillus subtilis lipase A play an important role in promoting the expression of APL. Furthermore, it was revealed that SP-LipA resulted in higher secretory expression compared to other signal peptides in this study primarily due to its encoding of N-terminal amino acids with relatively higher transcription levels and its efficient secretion capacity. Based on this foundation, the recombinant strain constructed in this work achieved a new record for the highest extracellular yields of APL in B. subtilis, reaching 12,295 U/mL, which was 1.9-times higher than that expressed in the recombinant Escherichia coli strain previously reported. The novel theories uncovered in this study are expected to play significant roles in enhancing the expression of foreign proteins both inside and outside of cells.