Publications by authors named "Ryo Matsunaga"

Protein phosphorylation is a crucial process in various cellular functions, and its irregularities have been implicated in several diseases, including cancer. Antibodies are commonly employed to detect protein phosphorylation in research. However, unlike the extensive studies on recognition mechanisms of the phosphate group by proteins such as kinases and phosphatases, only a few studies have explored antibody mechanisms.

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The thermal stability of trimeric lectin BC2L-CN was investigated and found to be considerably altered when mutating residue 83, originally a threonine, located at the fucose-binding loop. Mutants were analyzed using differential scanning calorimetry and isothermal microcalorimetry. Although most mutations decreased the affinity of the protein for oligosaccharide H type 1, six mutations increased the melting temperature (T) by >5 °C; one mutation, T83P, increased the T value by 18.

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Article Synopsis
  • Thermal stability is crucial for understanding protein properties; however, predicting it through machine learning has been challenging due to data quality issues and technical limitations in measuring protein denaturation.
  • Researchers developed a method to enhance throughput using Brevibacillus for protein secretion and efficient purification techniques, allowing analysis of 384 protein samples in just 4 days.
  • The study involved analyzing 186 mutants of a specific protein, revealing melting temperature variations that will aid in data-driven protein stability design and improve rational protein engineering strategies.
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Recent years have seen an uptick in the use of computational applications in antibody engineering. These tools have enhanced our ability to predict interactions with antigens and immunogenicity, facilitate humanization, and serve other critical functions. However, several studies highlight the concern of potential trade-offs between antibody affinity and stability in antibody engineering.

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Monoclonal antibodies are one of the fastest growing class of drugs. Nevertheless, relatively few biologics target multispanning membrane proteins because of technical challenges. To target relatively small extracellular regions of multiple membrane-spanning proteins, synthetic peptides, which are composed of amino acids corresponding to an extracellular region of a membrane protein, are often utilized in antibody discovery.

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For certain industrial applications, the stability of protein oligomers is important. In this study, we demonstrated an efficient method to improve the thermal stability of oligomers using the trimeric protein chloramphenicol acetyltransferase (CAT) as the model. We substituted all interfacial residues of CAT with alanine to detect residues critical for oligomer stability.

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Surface plasmon resonance (SPR) is widely used for antigen-antibody interaction kinetics analysis. However, it has not been used in the screening phase because of the low throughput of measurement and analysis. Herein, we proposed a high-throughput SPR analysis system named "BreviA" using the Brevibacillus expression system.

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The β-hairpin conformation is regarded as an important basic motif to form and regulate protein-protein interactions. Single-domain V H antibodies are potential therapeutic and diagnostic tools, and the third complementarity-determining regions of the heavy chains (CDR3s) of these antibodies are critical for antigen recognition. Although the sequences and conformations of the CDR3s are diverse, CDR3s sometimes adopt β-hairpin conformations.

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Interleukin-11 (IL-11) is a member of the interleukin-6 (IL-6) family of cytokines. IL-11 is a regulator of multiple events in hematopoiesis, and IL-11-mediated signaling is implicated in inflammatory disease, cancer, and fibrosis. All IL-6 family cytokines signal through the signal-transducing receptor, glycoprotein 130 (gp130), but these cytokines have distinct as well as overlapping biological functions.

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Listeriosis, caused by infection with Listeria monocytogenes, is a severe disease with a high mortality rate. The L. monocytogenes virulence factor, internalin family protein InlA, which binds to the host receptor E-cadherin, is necessary to invade host cells.

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Background: The outbreak of the 2019 novel coronavirus disease (COVID-19) led to an enforced quarantine period and limited training and match activities for athletes.

Purpose: To report the influence of the COVID-19 pandemic on the occurrence of injury in Japanese male professional soccer players.

Study Design: Descriptive epidemiology study.

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Unlabelled: The COVID-19 lockdown challenged the training options of athletes worldwide, including players from the most popular sport globally, football/soccer.

Purpose: The authors explored the training practices of football players worldwide during the COVID-19 lockdown.

Methods: Football players (N = 2482, 30% professional, 22% semipro, and 48% amateur) completed an online survey (May-July 2020) on their training practices before versus during lockdown (March-June 2020).

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Purpose: To investigate differences in athletes' knowledge, beliefs, and training practices during COVID-19 lockdowns with reference to sport classification and sex. This work extends an initial descriptive evaluation focusing on athlete classification.

Methods: Athletes (12,526; 66% male; 142 countries) completed an online survey (May-July 2020) assessing knowledge, beliefs, and practices toward training.

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Brevibacillus choshinensis is a gram-positive bacterium that is known to efficiently secrete recombinant proteins. However, the expression of these proteins is often difficult depending upon the expressed protein. In this study, we demonstrated that the addition of arginine hydrochloride and proline to the culture medium dramatically increased protein expression.

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Objective: Our objective was to explore the training-related knowledge, beliefs, and practices of athletes and the influence of lockdowns in response to the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Methods: Athletes (n = 12,526, comprising 13% world class, 21% international, 36% national, 24% state, and 6% recreational) completed an online survey that was available from 17 May to 5 July 2020 and explored their training behaviors (training knowledge, beliefs/attitudes, and practices), including specific questions on their training intensity, frequency, and session duration before and during lockdown (March-June 2020).

Results: Overall, 85% of athletes wanted to "maintain training," and 79% disagreed with the statement that it is "okay to not train during lockdown," with a greater prevalence for both in higher-level athletes.

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Anterior cruciate ligament (ACL) plays an essential role in knee joint stability and kinematics. The microstructural irregularities such as cellular changes and disorganization of the extracellular matrix (ECM) alter the mechanical properties of the ligament, leading to a significant knee functional instability and progression of osteoarthritis (OA). So far, the identification of the local abnormality in ACL has routinely relied on invasive analytical techniques such as histology or biochemical assays.

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Protein fibrils are expected to have applications as functional nanomaterials because of their sophisticated structures; however, nanoscale ordering of the functional units of protein fibrils remains challenging. Here we design a series of self-polymerizing protein monomers, referred to as protein shackles, derived from modified recombinant subunits of pili from Streptococcus pyogenes. The monomers polymerize into nanochains through spontaneous irreversible covalent bond formation.

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Since their first finding in wool 50years ago, keratin-associated proteins (KAPs), which are classified into three groups; high sulfur (HS) KAPs, ultra high sulfur (UHS) KAPs, and high glycine-tyrosine (HGT) KAPs, have been the target of curiosity for scientists due to their characteristic amino acid sequences. While HS and UHS KAPs are known to function in disulfide bond crosslinking, the function of HGT KAPs remains unknown. To clarify the function as well as the binding partners of HGT KAPs, we prepared KAP8.

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