Susumu Uchiyama

• Professor
• Professor (Full) at Osaka University

Synuclein (αSyn) inclusions are a pathological hallmark of several neurodegenerative disorders. While cryo‐electron microscopy studies have revealed distinct fibril polymorphs across different synucleinopathies, the molecular switches controlling polymorphism remain unveiled. In this study, we found that fibril morphology is associated with the con...

Recombinant adeno-associated virus (rAAV) has been widely used as an effective delivery tool in gene therapy. One of the challenges facing the production of high-quality rAAV is optimization of the production and purification methodologies. Cesium chloride density gradient ultracentrifugation (CsCl-DGUC) has been traditionally utilized for rAAV pur...

Recombinant adeno-associated virus (rAAV) has attracted attention as a gene therapy vector. Monitoring the percentage of full particles (FPs) to the sum of empty particles (EPs) and FPs (F/E ratio) is required to optimize the rAAV production conditions; however, there is a lack of analytical methods to identify FPs and EPs and quantify the F/E rati...

Protein aggregates and insoluble particles in biopharmaceutical products are impurities that can elicit immunogenicity. The protein aggregates and insoluble particles form during manufacturing and storage, and should be characterized to optimize the manufacturing process and establish a control strategy. Several issues regarding the evaluation and...

The role of viral protein (VP) 1 and VP2, which comprise the recombinant adeno-associated virus (rAAV) capsid, in heat-induced genome release was investigated using rAAV serotype 8 (rAAV8) samples with a high VP1/VP2 to VP3 ratio, a low VP1/VP2 to VP3 ratio, and VP3 only. The thermal unfolding of the VP1 N-termini was closely monitored by nano-diff...

Protein aggregates and particles in biopharmaceuticals can induce adverse immune responses in patients. Thus, suppression of the formation of protein aggregates and particles is important for the successful development of therapeutic proteins. Mechanical stresses, including agitation, are widely recognized as stress factors that generate protein ag...

The major challenges of gene therapy for hemophilia A using adeno-associated virus (AAV) vectors are reducing vector doses and the long-term maintenance of stable factor VIII (FVIII). Here, we developed engineered human B-domain-deleted FVIIIs (FVIIISQs) with enhanced secretion and coagulation potential. Intracellular accumulation was markedly redu...

Adeno-associated virus (AAV) vectors have attracted significant attention as the main platform for gene therapy. To ensure the safety and efficacy of AAV vectors when used as gene therapy drugs, it is essential to assess their critical quality attributes (CQAs). These CQAs include the genome packaging status, the size of the genome encapsidated wit...

Recombinant adeno-associated virus (rAAV) is a small, nonenveloped virus vector that has attracted attention as a gene therapy platform. Several studies have revealed the stability characteristics of rAAV; however, its tolerance against light stress remains unclear. Here, the physicochemical and biological impacts of light stress on rAAV6 with EGFP...

The adeno-associated virus (AAV) vector is one of the most advanced platforms for gene therapy because of its low immunogenicity and non-pathogenicity. The concentrations of both AAV vector empty particles, which do not contain DNA and do not show any efficacy, and AAV vector full particles (FPs), which contain DNA, are important quality attributes...

Immunoglobulin G (IgG) is a molecule that plays an important role in biological defense; IgG molecules have been applied as drugs due to their high specificity for antigens and their ability to activate immunity via effector molecules on immune cells. On the other hand, the flexibility of the hinge region makes it difficult to apply conventional st...

Microfiltration is an essential step during biopharmaceutical manufacturing. However, unexpected flux decay can occur. Although the flux decay profile and initial flux are important factors determining microfiltration filterability, predicting them accurately is challenging since the root cause of unexpected flux decay remains elusive. In this stud...

The higher-order structure (HOS) is a critical quality attribute of recombinant adeno-associated viruses (rAAVs). Evaluating the HOS of the entire rAAV capsid is challenging because of the flexibility and/or less folded nature of the VP1 unique (VP1u) and VP1/VP2 common regions, which are structural features essential for these regions to exert the...

Glycosylation of biopharmaceuticals can affect their safety and efficacy. Glycans can occur on recombinant adeno-associated viruses (rAAVs) that are used for gene therapy; however, the types of glycans that attach to rAAVs are controversial. Here, we conducted lectin microarray analyses on six rAAV serotype 6 (rAAV6) preparations that were produced...

Microfiltration (MF) is an essential step during biopharmaceutical manufacturing. However, unexpected flux decay can occur. Although the flux decay profile and initial flux are important factors determining MF filterability, predicting them accurately is challenging, as the root cause of unexpected flux decay remains elusive. In this study, the met...

Wnt proteins are thought to be transported in several ways in the extracellular space. For instance, they are known to be carried by exosomes and by Wnt-carrier proteins, such as sFRP proteins. However, little is known about whether and/or how these two transport systems are related. Here, we show that adding sFRP1 or sFRP2, but not sFRP3 or sFRP4,...

Environmentally regulated gene expression is critical for bacterial survival under stress conditions, including extremes in temperature, osmolarity and nutrient availability. Here, we dissect the thermo- and osmo-responsory behavior of the transcriptional repressor H-NS, an archetypal nucleoid-condensing sensory protein, ubiquitous in enterobacteri...

Adeno-associated virus (AAV) vectors are produced as a mixture of the desired particle (full particle, FP), which is filled with the designed DNA, product-related impurities such as particle without DNA (empty particle, EP), and aggregates. Cesium chloride or iodixanol equilibrium density gradient ultracentrifugation (DGE-UC) has been used for the...

Studies of recombinant adeno-associated virus (rAAV) revealed the mixture of full particles with different densities in rAAV. There are no conclusive results because of the lack of quantitative stoichiometric viral proteins, encapsidated DNA, and particle level analyses. We report the first comprehensive characterization of low- and high-density rA...

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LI-cadherin is a member of the cadherin superfamily. LI-cadherin mediates Ca²⁺-dependent cell–cell adhesion through homodimerization. A previous study reported two single nucleotide polymorphisms (SNPs) in the LI-cadherin-coding gene (CDH17). These SNPs correspond to the amino acid changes of Lys115 to Glu and Glu739 to Ala. Patients with colorecta...

Although interactions of small molecular drugs with serum proteins have been widely studied from pharmacokinetic and pharmacodynamic perspectives, there have been few reports on the effects of serum components on therapeutic antibody functions. This study reports the effect of abundant serum proteins on antibody-dependent cellular cytotoxicity (ADC...

Mass photometry (MP) is a label-free, single-molecule technique that can determine molecular mass distribution with very low sample consumption in a short time. Because of the established experimental instrument and analytical software, MP measurements may be readily obtained; thus, the application of MP is expanding, especially in the fields of bi...

Colonization of the host intestine is the most important step in Vibrio cholerae infection. The toxin-coregulated pilus (TCP), an operon-encoded type IVb pilus (T4bP), plays a crucial role in this process, which requires an additional secreted protein, TcpF, encoded on the same TCP operon; however, its mechanisms of secretion and function remain el...

LI-cadherin is a member of the cadherin superfamily. LI-cadherin mediates Ca ²⁺ -dependent cell-cell adhesion by forming a homodimer. A previous study reported two single nucleotide polymorphisms (SNPs) in the LI-cadherin-coding gene ( CDH17 ). These SNPs correspond to the amino acid changes of Lys115 to Glu and Glu739 to Ala. Patients with colorec...

Adeno-associated virus (AAV) vector is a promising platform for in vivo gene therapy. The accurate assessment of distribution state of particles contained in AAV vector samples is one of the most important and challenging matters and is necessary because the product-related impurities with the capsid structure (empty particles, intermediate particl...

Understanding a monoclonal antibody’s (MAb) physicochemical properties early in drug discovery is important for determining developability. Viscosity is important because antibodies with high viscosity have limited administration routes. Predicting the viscosity of highly concentrated MAb solutions is therefore essential for assessing developabilit...

An increase in protein aggregates during transportation should be suppressed in therapeutic protein products because the aggregates have a potential risk of immunogenicity. In this study, three protein solutions in vials were exposed to tri-axial vibration with various combinations of frequency and acceleration using a transportation test system to...

Subvisible particles (SVPs) are a critical quality attribute of parenteral and ophthalmic products. United States Pharmacopeia recommends the characterizations of SVPs which are classified into intrinsic, extrinsic, and inherent particles. Flow imaging microscopy (FIM) is useful as an orthogonal method in both the quantification and classification...

In this study, we conducted a collaborative study on the classification between silicone oil droplets and protein particles detected using the flow imaging (FI) method toward proposing a standardized classifier/model. We compared four approaches, including a classification filter composed of particle characteristic parameters, principal component a...

The interaction between IgG and Fc gamma receptor IIIa (FcγRIIIa) is essential for mediating immune responses. Recent studies have shown that the antigen binding fragment (Fab) and Fc are involved in IgG-FcγRIII interactions. Here, we conducted bio-layer interferometry (BLI) and isothermal titration calorimetry to measure the kinetic and thermodyna...

Disaggregation of amyloid fibrils is a fundamental biological process required for amyloid propagation. However, due to the lack of experimental systems, the molecular mechanism of how amyloid is disaggregated by cellular factors remains poorly understood. Here, we established a robust in vitro reconstituted system of yeast prion propagation and fo...

BRAC1 associated protein-1 (BAP1) is a major tumor suppressor involved in many cancers. The deubiquitinase (DUB) activity of BAP1 is essential for its nuclear localization, histone remodeling and proteostasis associated with mitochondrial calcium flux. Loss of the DUB activity due to catalytic mutations within the ubiquitin C-terminal hydrolase (UC...

Cancer-specific cell surface antigens are ideal therapeutic targets for monoclonal antibody (mAb)–based therapy. Here, we report that multiple myeloma (MM), an incurable hematological malignancy, can be specifically targeted by an mAb that recognizes a ubiquitously present protein, CD98 heavy chain (hc) (also known as SLC3A2). We screened more than...

α-Synuclein inclusions are a pathological hallmark of several neurodegenerative diseases. Although it has been demonstrated a relationship between fibril polymorphism and different pathologies, the molecular origins of polymorphism are not understood. Employing biophysical approaches, we revealed that the conformational state of the monomeric αSyn...

Recently, an international randomized controlled clinical trial showed that patients with SARS-CoV-2 infection treated orally with the 3-chymotrypsin-like protease (3CLpro) inhibitor PF-07321332 within three days of symptom onset showed an 89% lower risk of COVID-19-related hospital admission/ death from any cause as compared with the patients who...

Antibody drugs have heterogeneity, and therefore, the evaluation of the physical properties of antibodies are required to obtain the accurate amount of the target protein as an active ingredient and its impurities for the control of drug substances. Furthermore, it is also important to investigate the physical properties of the antibody that affect...

Recombinant adeno-associated virus (rAAV) vectors have proven efficacy as gene therapy vehicles. However, non-specific adsorption of these vectors on solid surfaces is encountered during production, storage, and administration, as well as in quantification processes. Such adsorption has been reported to result in the loss of up to 90% of vector par...

To reduce the risk of infection during intravitreal injections, the external surface of prefilled syringes (PFSs) must be sterilized. Usually, ethylene oxide (EO) gas or vaporized hydrogen peroxide (VHP) is used for sterilization. More recently, nitrogen dioxide (NO2) gas sterilization has been developed. It is known that gas permeability is approx...

LI-cadherin is a member of the cadherin superfamily, which encompasses a group of Ca²⁺-dependent cell adhesion proteins. The expression of LI-cadherin is observed on various types of cells in the human body, such as normal small intestine and colon cells, and gastric cancer cells. Because its expression is not observed on normal gastric cells, LI-c...

The assessment of aggregates is essential in biopharmaceutical development. Although submicron-sized aggregates are considered to have a potential immunogenicity risk, analytical techniques are limited. In this study, we present a new analytical technique using three-dimensional homodyne light detection (3D-HLD). In this system, submicron-sized par...

Protein aggregate formation in prefilled syringes (PFSs) can be influenced by protein adsorption and desorption at the solid–liquid interface. Although inhibition of protein adsorption on the PFS surface can lead to a decrease in the amount of aggregation, the mechanism underlying protein adsorption-mediated aggregation in PFSs is unclear. This stu...

Progesterone receptor membrane component 1 (PGRMC1) is highly expressed in various cancer cells and contributes to tumor progression. We have previously shown that PGRMC1 forms a unique heme-stacking functional dimer to enhance EGF receptor (EGFR) activity required for cancer proliferation and chemoresistance, and the dimer dissociates by carbon mo...

Recombinant adeno-associated virus (rAAV) is a leading platform in human gene therapy. The AAV capsid is composed of three viral proteins (VPs): VP1, VP2, and VP3. To ensure the safety of AAV-based gene therapy products, the stoichiometry of VPs of AAV vector should be carefully monitored. Here, SDS-PAGE, capillary gel electrophoresis (CGE), and li...

During the manufacturing of recombinant adeno-associated virus vectors, it is generally difficult to purify out vectors that lack nucleic acids (empty particles, EPs), contain incomplete nucleic acids (intermediate particles, IPs) or aggregates. These impurities may cause side effects and therefore it is essential to both quantify and reduce them;...

Attractive self-interaction processes in antibody formulations increase the risk of aggregation and extraordinarily elevated viscosity at high protein concentrations. These challenges affect manufacturing and application. This study aimed to understand the self-interaction process of Infliximab as a model system with pronounced attractive self-inte...

IgA antibodies, which are secreted onto the mucosal surface as secretory IgA antibodies (SIgAs), play an important role in preventing influenza virus infection. A recent study reported that anti-hemagglutinin (HA) head-targeting antibodies increase anti-viral functions such as hemagglutination inhibition (HI) and virus neutralization (NT), in addit...

Upscaling the production capacity of inactivated poliovirus vaccines (IPV) is urgently needed to eradicate polio worldwide. For the development of a robust manufacturing process for IPV, the impact of stresses on the properties of the poliovirus during manufacturing needs to be carefully evaluated. In this study, the physicochemical properties of S...

Disaggregation of amyloid fibrils is a fundamental biological process required for amyloid propagation. However, due to the lack of experimental systems, the molecular mechanism of how amyloid is disaggregated by cellular factors remains poorly understood. Here, we established a robust, in vitro reconstituted system of yeast prion propagation and f...

Background SARS-CoV-2 genome accumulates point mutations in a constant manner. Whether the accumulation of point mutations is correlated with milder manifestations of COVID-19 remains unknown. Methods We performed SARS-CoV-2 genome sequencing in 90 patients with COVID-19 infection treated at a tertiary medical center in Tokyo between March and Aug...

Introduction: Several new biopharmaceutical dosage forms have developed over time, such as lyophilized vial, liquid vial, and liquid prefilled syringe formulations. Due to the research and development of such biopharmaceutical formulations, they can be stored with high stability even at high protein concentrations. This review summarizes major phar...

Xeno nucleic acids, which are synthetic analogues of natural nucleic acids, have potential for use in nucleic acid drugs and as orthogonal genetic biopolymers and prebiotic precursors. Although few acyclic nucleic acids can stably bind to RNA and DNA, serinol nucleic acid (SNA) and L-threoninol nucleic acid (L-aTNA) stably bind to them. Here we dis...

LI-cadherin is a member of cadherin superfamily which is a Ca ²⁺ -dependent cell adhesion protein. Its expression is observed on various types of cells in the human body such as normal small intestine and colon cells, and gastric cancer cells. Because its expression is not observed on normal gastric cells, LI-cadherin is a promising target for gast...

Guanosine 5′-monophosphate reductase (GMPR) is involved in the purine salvage pathway and is conserved throughout evolution. Nonetheless, the GMPR of Trypanosoma brucei (TbGMPR) includes a unique structure known as the cystathionine-β-synthase (CBS) domain, though the role of this domain is not fully understood. Here, we show that guanine and adeni...

We oxidized histidine residues in monoclonal antibody drugs of immunoglobulin gamma 1 (IgG1) using ultraviolet C irradiation (UVC: 200–280 nm), which is known to be potent for sterilization or disinfection. Among the reaction products, we identified asparagine and aspartic acid by mass spectrometry. In the photo-induced oxidation of histidine in an...

Intravitreal injections have become the most commonly performed intraocular treatments worldwide. Because intravitreal injections may induce severe adverse events, such as infectious and noninfectious endophthalmitis, cataract, ocular hypertension, vitreous hemorrhage, or retinal detachment, appropriate awareness of the materials and techniques use...

Isothermal titration calorimetry (ITC) directly provides thermodynamic parameters depicting the energetics of intermolecular interactions in solution. During ITC experiments, a titration syringe with a paddle is continuously rotating to promote a homogeneous mixing. Here, we clarified that the shape of the paddles (flat, corkscrew, and small-pitche...

Serinol nucleic acid (SNA) is promising for nucleic acid‐based drugs due to its affinity to RNA. However, stable self‐hybridization of SNA in short complementary regions hinders hetero‐hybridization with RNA. It is thus crucial to suppress self‐hybridization for promoting SNA‐RNA hybridization. Herein, suitable protocols were developed for the prep...

Serinol nucleic acid (SNA) is a promising candidate for nucleic acid‐based molecular probes and drugs due to its high affinity for RNA. Our previous work revealed that incorporation of 2,6‐diaminpurine (D), which can form three hydrogen bonds with uracil, into SNA increases the melting temperature of SNA‐RNA duplexes. However, D incorporation into...

Banana ripening is a complex molecular process that produces visible changes in the texture, aroma, taste and nutritional content. Ripening is controlled by genetic code, metabolic pathway and associated microbiome. We reported the microbial community structure during banana ripening with alcohol treatment to discover endophytic and epiphytic micro...

Euryarchaeal genomes encode proteasome-assembling chaperone homologs, PbaA and PbaB, although archaeal proteasome formation is a chaperone-independent process. Homotetrameric PbaB functions as a proteasome activator, while PbaA forms a homopentamer that does not interact with the proteasome. Notably, PbaA forms a complex with PF0014, an archaeal pr...

As reported in the previous commentary (Ishii-Watabe et al., J Pharm Sci 2017), the Japanese biopharmaceutical research group is promoting collaborative multi-laboratory studies to evaluate and standardize new methodologies for biopharmaceutical characterization and quality control. We have conducted the studies and held two annual meetings in 2018...

True understanding of dispersion interaction in solution remains elusive because of difficulty in the precise evaluation of its interaction energy. Here, the effect of substituents with different polarizability on dispersion interactions in water is discussed based on the thermodynamic parameters determined by isothermal titration calorimetry for t...

Several accessory proteins are required for the assembly of the metal centers in hydrogenases. In NiFe-hydrogenases, CO and CN− are coordinated to the Fe in the NiFe dinuclear cluster of the active center. Though these diatomic ligands are biosynthesized enzymatically, detail mechanisms of their biosynthesis remain unclear. Here, we report the stru...

The design of injection devices, including pre-filled syringes (PFSs) and auto-injectors, requires an understanding of the optimization of injection conditions. The injection of highly-concentrated biopharmaceuticals can lead to exceptionally high injection forces, due to their high viscosity. To overcome this challenge, a tapered needle has been r...

Aggregation of therapeutic monoclonal antibodies have a potential risk of immunogenicity, requiring minimization of aggregate formation. We have developed a fitting formula for antibody aggregation at 40°C based on physicochemical parameters, including colloidal and conformational stabilities. An IgG1 monoclonal antibody, MAb-T, was formulated in 2...

A novel approach to identify five types of simulated stresses that induce protein aggregation in pre-filled syringe (PFS)-type biopharmaceuticals was developed. Principal components analyses of texture metrics extracted from flow imaging microscopy images were used to define sub-groups of particles. Supervised machine learning methods including con...

The central oscillator generating cyanobacterial circadian rhythms comprises KaiA, KaiB, and KaiC proteins. Their interactions cause KaiC phosphorylation and dephosphorylation cycles over approximately 24 h. KaiB interacts with phosphorylated KaiC in competition with SasA, an output protein harboring a KaiB-homologous domain. Structural data have i...

Most cells active in the immune system express receptors for antibodies which mediate a variety of defensive mechanisms. These receptors interact with the Fc portion of the antibody and are therefore collectively called Fc receptors. Here, using high-speed atomic force microscopy, we observe interactions of human, humanized, and mouse/human-chimeri...

Protein tyrosine phosphatase receptor type Z (PTPRZ) has two receptor isoforms PTPRZ-A and -B, containing tandem intracellular PTP-D1 and -D2 domains, with only D1 being active. Pleiotrophin (PTN) binding to the extracellular PTPRZ region leads to inactivation of its PTPase activity, thereby facilitating oligodendrocyte precursor cell (OPC) differe...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The cyanobacterial clock is controlled via the interplay among KaiA, KaiB, and KaiC, which generate a periodic oscillation of KaiC phosphorylation in the presence of ATP. KaiC forms a homohexamer harboring 12 ATP-binding sites and exerts ATPase activities associated with its autophosphorylation and dephosphorylation. The KaiC nucleotide state is a...

Protein tyrosine phosphatase receptor type Z (PTPRZ) has two receptor isoforms (PTPRZ-A and -B) containing tandem PTP-D1 and -D2 domains intracellularly, with only D1 being active. Pleiotrophin (PTN) binding to the extracellular region of PTPRZ leads to the inactivation of PTPase, thereby inducing oligodendrocyte precursor cell (OPC) differentiatio...

Eukaryotic proteasomes harbor heteroheptameric α-rings, each composed of seven different but homologous subunits α1–α7, which are correctly assembled via interactions with assembly chaperones. The human proteasome α7 subunit is reportedly spontaneously assembled into a homotetradecameric double ring, which can be disassembled into single rings via...

Separation of a homogeneous mixture of different components to reach an ordered out-of-equilibrium state in solution has attracted continuous attention. While this can be achieved using external chemical fuels or photo energy, an alternative energy source is heat. Here we realize a temperature-controlled cycle of transitions between ordered and dis...

Antibody aggregates are a potential risk for immunogenicity; therefore, rational approaches to improve associated aggregation properties need to be developed. Here, we report the amino acid region responsible for aggregation initiation. Two types of therapeutic IgG1 antibody monomer samples were prepared: IgG1 mAb40-3M stored at 40°C for 3 months,...

Phospholipase A2 (PLA2) is one of the representative toxic components of snake venom. PLA2s are categorized into several subgroups according to the amino acid at position 49, which comprises either Asp49, Lys49, Arg49 or Ser49. Previous studies suggested that the Lys49-PLA2 assembles into an extremely stable dimer. Although the behavior on Sodium d...