Journal of bioscience and bioengineering最新文献

{"title":"Structural and functional analysis of l-methionine oxidase identified through sequence data mining","authors":"Yui Kawamura,&nbsp;Sayaka Sugiura,&nbsp;Hayato Araseki,&nbsp;Taichi Chisuga,&nbsp;Shogo Nakano","doi":"10.1016/j.jbiosc.2024.07.014","DOIUrl":"10.1016/j.jbiosc.2024.07.014","url":null,"abstract":"<div><div><span>l</span>-Amino acid oxidase (LAAO), an FAD-dependent enzyme, catalyzes the oxidation of <span>l</span>-amino acids (<span>l</span>-AAs) to their corresponding imino acids. While LAAOs, which can oxidize charged or aromatic <span>l</span>-AAs specifically, have been extensively characterized across various species, LAAOs that have high specificity toward alkyl-chain <span>l</span>-AAs, such as <span>l</span>-Met, are hardly characterized for now. In this study, we screened a highly specific <span>l</span>-Met oxidizing LAAOs from <em>Burkholderiales</em> bacterium (BbMetOx) and <em>Undibacterium</em> sp. KW1 (UndMetOx) using sequence similarity network (SSN) analysis. These enzymes displayed an order of magnitude higher specific activity towards <span>l</span>-Met compared to other <span>l</span>-AAs. Enzyme activity assays showed that these LAAOs operate optimally at moderate condition because the optimal pH and <em>T</em>_m values were pH 7.0 and 58–60°C. We determined the crystal structures of wild-type BbMetOx (BbMetOx(WT)) and an inactivated mutant, BbMetOx (K304A), at 2.7 Å and 2.2 Å resolution, respectively. The overall structure of BbMetOx is closely similar to other known LAAOs of which structures were determined. Comparative analysis of the BbMetOx structures revealed significant conformational changes in the catalytic domain, particularly a movement of approximately 8 Å in the C_α atom of residue Y180. Further analysis highlighted four residues, i.e., Y180, M182, F300, and M302, as critical for <span>l</span>-Met recognition, with alanine substitution at these positions resulting in loss of activity. This study not only underscores the utility of SSN for discovering novel LAAOs but also advances our understanding of substrate specificity in this enzyme family.</div></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 5","pages":"Pages 391-398"},"PeriodicalIF":2.3,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141982307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Screening of protein-based inhibitors for the intracellular domain of epidermal growth factor receptor by directed evolution using the yeast Gγ recruitment system","authors":"Ririka Asama ,&nbsp;Masahiro Tominaga ,&nbsp;Sayaka Ito ,&nbsp;Yoichiro Ito ,&nbsp;Kazuhiro Takemura ,&nbsp;Shun Sakuraba ,&nbsp;Kohei Katsurada ,&nbsp;Nobuo Fukuda ,&nbsp;Akihiko Kondo ,&nbsp;Jun Ishii","doi":"10.1016/j.jbiosc.2024.07.007","DOIUrl":"10.1016/j.jbiosc.2024.07.007","url":null,"abstract":"<div><div>Protein-based therapeutics, including antibodies and antibody-like-proteins, have increasingly attracted attention due to their high specificity compared to small-molecular drugs. The Gγ recruitment system, one of the <em>in vivo</em> yeast two-hybrid systems for detecting protein–protein interactions, has been previously developed using yeast signal transduction machinery. In this study, we modified the Gγ recruitment system to screen the protein mutants that efficiently bind to the intracellular domain of the epidermal growth factor receptor L858R mutant (cytoEGFR^L858R). Using the modified platform, we performed <em>in vivo</em> directed evolution for growth factor receptor-bound protein 2 (Grb2) and its truncated variant containing only the Src-homology 2 (SH2) domain, successfully identifying several mutants that more strongly bound to cytoEGFR^L858R than their parental proteins. Some of them contained novel beneficial mutations (F108Y and Q144H) and specifically bound to the recombinant cytosolic phosphorylated EGFR <em>in vitro</em>, highlighting the utility of the evolutionary platform.</div></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 5","pages":"Pages 375-381"},"PeriodicalIF":2.3,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141912839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transcriptomic analysis reveals insights into the responses of Synechocystis sp. PCC 6803 to acidification during cultivation with ammonium salts as a nitrogen source","authors":"Kotaro Kobayashi ,&nbsp;Kohei Yoneda ,&nbsp;Yoshiaki Maeda ,&nbsp;Iwane Suzuki","doi":"10.1016/j.jbiosc.2024.07.005","DOIUrl":"10.1016/j.jbiosc.2024.07.005","url":null,"abstract":"<div><p>Utilizing ammonium in wastewater is a prospective way to reduce costs for bioproduction by photosynthetic organisms. A model cyanobacterium <em>Synechocystis</em> sp. PCC 6803 takes advantage of tolerance to ammonium compared to other microalgae. However, in this study, we report that <em>Synechocystis</em> growth was inhibited when cultured in a medium containing ammonium. This may be due to the pH decreasing below 6 caused by consuming ammonium. Transcriptomic analysis by RNA-seq revealed that the expression of the genes for proteases, chaperones, and antioxidant-scavenging enzymes was induced, but photosynthetic components were repressed. Although these regulations are similar to the previous studies on acidic stress in nitrate-containing culture, the expression of genes such as <em>sigD</em>, <em>slr0042</em>, <em>slr0373</em>, <em>slr0374</em>, and <em>slr1501</em> was different, indicating that these phenomena are not simply identical to the known responses to acidic stress. The expression of the genes for photosynthesis, gluconeogenesis, and nitrogen assimilation was repressed, and glycolysis and the tricarboxylic acid cycle were induced. Despite the up-regulation of the carbon catabolism and down-regulation of nitrogen assimilation, the 2-oxoglutarate content in the ammonium-grown cells was lower than that in the nitrate-grown cells, and the contents of the major amino acids, such as Glu, Ala, Asp, and Gly were decreased, while the minor amino acids were the same or increased, especially Arg, Lys, Val, and Ile. These results demonstrated that the acidic stress induced by the consumption of ammonium ions differs from the sudden pH drop, and the <em>Synechocystis</em> cell manages amino acid levels to endure carbon limitation under the stress.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 261-270"},"PeriodicalIF":2.3,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141901913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel multifunctional plant growth-promoting bacteria isolated from the oil palm rhizosphere under long-term organic matter application","authors":"Fandi Hidayat ,&nbsp;Rizki Desika Putri Pane ,&nbsp;Fadilla Sapalina ,&nbsp;Eka Listia ,&nbsp;Winarna ,&nbsp;Muhammad Edwin Syahputra Lubis ,&nbsp;Mugihito Oshiro ,&nbsp;Kenji Sakai ,&nbsp;Yukihiro Tashiro","doi":"10.1016/j.jbiosc.2024.07.008","DOIUrl":"10.1016/j.jbiosc.2024.07.008","url":null,"abstract":"<div><div>Most agricultural products are presently cultivated on marginal lands with poor soil properties and unfavorable environmental conditions (diseases and abiotic stresses), which can threaten plant growth and yield. Plant growth-promoting bacteria (PGPB) are beneficial bacteria that promote plant growth and biomass and act as biocontrols against diseases and stress. However, most isolated PGPBs have a single function and low survival rates owing to their limited growth behaviors. In this study, we isolated multifunctional PGPB from oil palm rhizosphere, quantitatively measured their activities, and evaluated their effectiveness in <em>Brassica rapa</em> (Komatsuna) cultivation. This is the first study to report the isolation of three multifunctional PGPB strains with ammonium production, phosphate-potassium-silicate solubilization, and indole-3-acetic acid (IAA) production from the oil palm rhizosphere, namely <em>Kosakonia oryzendophytica</em> AJLB38, <em>Enterobacter quasimori</em> AJTS77, and <em>Lelliottia jeotgali</em> AJTS83. Additionally, these strains showed antifungal activity against the oil palm pathogen <em>Ganoderma boninense</em>. These strains grow under high temperature, acidic and alkaline pH, and high salt concentration, which would result in their proliferation in various environmental conditions. The cultivation experiments revealed these strains improved the growth and biomass with half the dosage of chemical fertilizer application, which was not significantly different to the full dosage. Furthermore, the overall plant growth-promoting activities in quantitative assays and overall <em>B. rapa</em> growth in cultivation experiments were statistically correlated, which could contribute to the prediction of plant growth promotion without plant cultivation experiments. Thus, the selected PGPB could be valuable as a biofertilizer to improve soil health and quality and promote agricultural sustainability.</div></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 5","pages":"Pages 406-414"},"PeriodicalIF":2.3,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141901912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Individual evaluation of nitrite and free nitrous acid inhibition on anammox activity","authors":"Koya Hirose ,&nbsp;Takashi Kondo ,&nbsp;Yayoi Saito ,&nbsp;Kazuichi Isaka","doi":"10.1016/j.jbiosc.2024.06.010","DOIUrl":"10.1016/j.jbiosc.2024.06.010","url":null,"abstract":"<div><p>The anammox reaction simultaneously utilizes ammonia and nitrite as substrates; however, high nitrite concentrations act as strong inhibitors of the reaction. In this study, inhibition by NO₂⁻ and free nitrous acid (FNA) was separately evaluated in continuous feeding tests using different biomass carriers. The influent NO₂⁻ concentration was increased under pH 7.6, where FNA is less likely to affect anammox activity. A continuous test using polyethylene glycol (PEG) gel carriers containing immobilized anammox bacteria showed that the inhibition ratio was 13% when the NO₂⁻-N concentration in the reactor was 350 mg L⁻¹ (FNA ≤0.06 mg L⁻¹). The relationship between NO₂⁻ concentration in the reactor and inhibition ratio increased linearly. Evaluation of the inhibitory effect of FNA by increasing the influent NO₂⁻ concentration at pH 6.4, where FNA is easily formed, demonstrated that the relationship between FNA and inhibition ratio could be fitted to a sigmoid curve, and the 50% inhibitory concentration (IC₅₀) of FNA was 0.88 mg L⁻¹. A similar test performed using polyvinyl alcohol carriers containing anammox bacteria on their surface showed the same trend as the PEG gel carriers, with the IC₅₀ for FNA at 0.70 mg L⁻¹. These results indicate that the inhibitory effect of FNA on anammox activity was greater than that of NO₂⁻. The evaluation of these two factors helped identify important operational indicators of the stable application of anammox processes.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 345-350"},"PeriodicalIF":2.3,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141897530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physiological responses contributing to multiple stress tolerance in Pichia kudriavzevii with potential enhancement for ethanol fermentation","authors":"Pongsanat Pongcharoen ,&nbsp;Wittaya Tawong ,&nbsp;Wanwarang Pathaichindachote ,&nbsp;Weerawan Rod–in","doi":"10.1016/j.jbiosc.2024.07.012","DOIUrl":"10.1016/j.jbiosc.2024.07.012","url":null,"abstract":"<div><p>Economically feasible ethanol production requires efficient hydrolysis of lignocellulosic biomass and high–temperature processing to enable simultaneous saccharification and fermentation. During the lignocellulolysic hydrolysate, the yeast must encounter with a multiple of inhibitors such as heat and furfural. To solve this problem, a potential fermentative yeast strain that tolerated simultaneous multistress and enhance ethanol concentration was investigated. Twenty yeast isolates were classified into two major yeast species, namely <em>Pichia kudriavzevii</em> (twelve isolates) and <em>Candida tropicalis</em> (eight isolates). All <em>P. kudriavzevii</em> isolates were able to grow at high temperature (45 °C) and exhibited stress tolerance toward furfural. Among <em>P. kudriavzevii</em> isolates, NUCG–S3 presented the highest specific growth rate under each stress condition of heat and furfural, and multistress. Morphological changes in <em>P. kudriavzevii</em> isolates (NUCG–S2, NUCG–S3, NUKL–P1, NUKL–P3, and NUOR–J1) showed alteration in mean cell length and width compared to the non–stress condition. Ethanol production by glucose was also determined. The yeast strain, NUCG–S3, gave the highest ethanol concentrations at 99.46 ± 0.82, 62.23 ± 0.96, and 65.80 ± 0.62 g/l (<em>P</em> &lt; 0.05) under temperature of 30 °C, 40 °C, and 42 °C, respectively. The tolerant isolated yeast NUCG–S3 achieved ethanol production of 53.58 ± 3.36 and 48.06 ± 3.31 g/l (<em>P</em> &lt; 0.05) in the presence of 15 mM furfural and multistress (42 °C with 15 mM furfural), respectively. Based on the results of the present study, the novel thermos and furfural-tolerant yeast strain <em>P. kudriavzevii</em> NUCG–S3 showed promise as a highly proficient yeast for high–temperature ethanol fermentation.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 314-323"},"PeriodicalIF":2.3,"publicationDate":"2024-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141889344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Regioselective photocyclodimerization of 2-anthracenecarboxylic acid through ATP hydrolysis-driven conformational change using simulation prediction-designed GroEL mutant","authors":"Masaki Nishijima ,&nbsp;Kota Kobayashi ,&nbsp;Megumi Masuda-Endo ,&nbsp;Hiromi Yoda ,&nbsp;Ayumi Koike-Takeshita","doi":"10.1016/j.jbiosc.2024.07.002","DOIUrl":"10.1016/j.jbiosc.2024.07.002","url":null,"abstract":"<div><p>GroEL, a chaperone protein responsible for peptide and denatured protein folding, undergoes substantial conformational changes driven by ATP binding and hydrolysis during folding. Utilizing these conformational changes, we demonstrated the GroEL-mediated regioselective photocyclodimerization of 2-anthracenecarboxylic acid (AC) using ATP hydrolysis as an external stimulus. We designed and prepared an optimal GroEL mutant to employ in a docking simulation that has been actively used in recent years. Based on the large difference in the motif of hydrogen bonds between AC and GroEL mutant compared with the wild-type, we predicted that GroEL^MEL, in which the 307‒309th amino acid residues were mutated to Ala, could alter the orientation of bound AC in GroEL. The GroEL^MEL-mediated photocyclodimerization of AC can be used for regioselective inversion upon ATP addition to a moderate extent.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 283-289"},"PeriodicalIF":2.3,"publicationDate":"2024-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141889345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peptide array screening with anti-GLP-1 monoclonal antibody: Discovery of cysteine-containing DPP-IV inhibitory peptides","authors":"Masaki Kurimoto ,&nbsp;Naoki Yuda ,&nbsp;Masayoshi Tanaka ,&nbsp;Miyuki Tanaka ,&nbsp;Mina Okochi","doi":"10.1016/j.jbiosc.2024.07.001","DOIUrl":"10.1016/j.jbiosc.2024.07.001","url":null,"abstract":"<div><p>Inhibition of dipeptidyl peptidase IV (DPP-IV) is an effective pharmacotherapy for the management of type 2 diabetes. Recent findings have suggested that various dietary proteins can serve as precursors to peptides that inhibit DPP-IV. Although several DPP-IV inhibitory peptides derived from food materials have been reported, more effective inhibitory peptides remain to be discovered. This study aimed to identify potent DPP-IV inhibitory peptides that earlier approaches had overlooked by employing a screening method that combined peptide arrays and neutralizing antibodies. Octa-peptides covering the complete amino acid sequences of four casein proteins and two whey proteins were synthesized on arrays via a solid-phase method. These peptides were then reacted with a monoclonal antibody specifically engineered to recognize glucagon-like peptide 1 (GLP-1), a substrate of DPP-IV. The variable region of the anti-GLP-1 monoclonal antibody is utilized to mimic the substrate-binding region of DPP-IV, enabling the antibody to bind to peptides that interact with DPP-IV. Based on this feature, 26 peptides were selected as DPP-IV inhibitory peptide candidates, 11 of which showed strong DPP-IV inhibitory activity. Five of these peptides consistently contained cysteines positioned two to four residues from the N-terminus. Treatment with disulfide formation decreased the DPP-IV inhibitory activity of these cysteine-containing peptides, while the inhibitory activity of α-lactalbumin hydrolysates increased with reducing treatment. These results revealed that the thiol group is important for DPP-IV inhibitory activity. This study provides a useful screen for DPP-IV inhibitory peptides and indicates the importance of reductive cysteine residues within DPP-IV inhibitory peptides.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 351-359"},"PeriodicalIF":2.3,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141859879","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation of arginine deiminase system-deficient mutants of Tetragenococcus halophilus using arginine analog canavanine","authors":"Takura Wakinaka ,&nbsp;Jun Watanabe ,&nbsp;Yoshinobu Mogi","doi":"10.1016/j.jbiosc.2024.07.006","DOIUrl":"10.1016/j.jbiosc.2024.07.006","url":null,"abstract":"<div><p>Arginine deimination by <em>Tetragenococcus halophilus</em>, a halophilic lactic acid bacterium, is an undesirable reaction in soy sauce brewing because it is responsible for the production of ethyl carbamate, a potential carcinogen. Therefore, arginine deiminase system-deficient mutants have been generated and used as starter cultures. However, the pre-existing screening method for arginine deiminase system-deficient mutants was time consuming. To reduce the burden of this screening process, we established a method to isolate mutants incapable of arginine deimination using the arginine analog canavanine. Strains lacking arginine deiminase system were less sensitive to canavanine than wild type strain, which is likely because arginine deiminase consumes arginine in the cytoplasm and increases the relative concentration of canavanine in the cells and enhances its toxicity. This report provides an industrially useful method to efficiently obtain arginine deiminase system-deficient mutants.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 324-327"},"PeriodicalIF":2.3,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141855568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rational design approach to improve the solubility of the β-sandwich domain 1 of a thermophilic protein","authors":"Chukwuebuka M. Ononugbo ,&nbsp;Yusaku Shimura ,&nbsp;Noriko Yamano-Adachi ,&nbsp;Takeshi Omasa ,&nbsp;Yuichi Koga","doi":"10.1016/j.jbiosc.2024.06.009","DOIUrl":"10.1016/j.jbiosc.2024.06.009","url":null,"abstract":"<div><p>The β-sandwich domain 1 (SD1) of islandisin is a stable thermophilic protein with surface loops that can be redesigned for specific target binding, architecturally comparable to the variable domain of immunoglobulin (IgG). SD1's propensity to aggregate due to incorrect folding and subsequent accumulation in <em>Escherichia coli</em> inclusion bodies limits its use in biotechnological applications. We rationally designed SD1 for improved variants that were expressed in soluble forms in <em>E. coli</em> while maintaining the intrinsic thermal stability of the protein (melting temperature (Tm) = 73). We used FoldX's ΔΔG predictions to find beneficial mutations and aggregation-prone regions (APRs) using Tango. The S26K substitution within protein core residues did not affect protein stability. Among the soluble mutants studied, the S26K/Q91P combination significantly improved the expression and solubility of SD1. We also examined the effects of the surface residue, pH, and concentration on the solubility of SD1. We showed that the surface polarity of proteins had little or no effect on solubility, whereas surface charges played a substantial role. The storage stability of several SD1 variants was impaired at pH values near their isoelectric point, and pH levels resulting in highly charged groups. We observed that mutations that create an uneven distribution of charged groups on the SD1 surface could enhance protein solubility by eliminating favorable protein–protein surface charge interactions. Our findings suggest that SD1 is mutationally tolerant to new functionalities, thus providing a novel perspective for the application of rational design to improve the solubility of targeted proteins.</p></div>","PeriodicalId":15199,"journal":{"name":"Journal of bioscience and bioengineering","volume":"138 4","pages":"Pages 271-282"},"PeriodicalIF":2.3,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141792523","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}