Search

Chemical and enzymatic modifications of peptide-displayed libraries have been successfully employed to expand the phage display library. However, the requirement of specific epitopes and scaffolds has limited the scope of protein engineering using phage display. In this study, we present a novel approach utilizing omniligase-1-mediated selective and specific ligation on the phage pIII protein, offering a high conversion rate and compatibility with commercially available phage libraries. We applied this method to perform high-throughput engineering of insulin analogues with randomized B chain C-terminal regions. Insulin analogues with different B chain C-terminal segments were selected and exhibited biological activity equivalent to that of human insulin. Molecular dynamics studies of insulin analogues revealed a novel interaction between the insulin B27 residue and insulin receptor L1 domain. In summary, our findings highlight the potential of omniligase-1-mediated phage display in the development and screening of disulfide-rich peptides and proteins. This approach holds promise for the creation of novel insulin analogues with enhanced therapeutic properties and exhibits potential for the development of other therapeutic compounds.

We developed a new cysteine-specific solubilizing tag strategy via a cysteine-conjugated succinimide. This solubilizing tag remains stable under common native chemical ligation conditions and can be efficiently removed with palladium-based catalysts. Utilizing this approach, we synthesized two proteins containing notably difficult peptide segments: interleukin-2 (IL-2) and insulin. This IL-2 chemical synthesis represents the simplest and most efficient approach to date, which is enabled by the cysteine-specific solubilizing tag to synthesize and ligate long peptide segments. Additionally, we synthesized a T8P insulin variant, previously identified in an infant with neonatal diabetes. We show that T8P insulin exhibits reduced bioactivity (a 30-fold decrease compared to standard insulin), potentially contributing to the onset of diabetes in these patients. In summary, our work provides an efficient tool to synthesize challenging proteins and opens new avenues for exploring research directions in understanding their biological functions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Insulin derivatives provide new functions that are distinctive from native insulin. We investigated insulin modifications on the C-terminal A chain with insulin receptor (IR) peptide binders and presented a full and potent IR antagonist. We prepared insulin precursors featuring a sortase A (SrtA) recognition sequence, LPETGG, at the C-terminal A chain and used a SrtA-mediated ligation method to synthesize insulin derivatives. The insulin precursor exhibits full IR agonism potency, similar to native human insulin. We explored derivatives with linear IR binding peptides attached to the insulin C-terminal A chain. One insulin derivative with an IR binder (Ins-AC-S2) can fully antagonize IR activation by insulin, as confirmed by cell-based assays. This IR antagonist suppresses insulin-induced hypoglycemia in a streptozotocin-induced diabetic rat model. This study provides a new direction toward insulin antagonist development.

A platform to enable precise modifications of insulin could improve drug functionality.

Glucose-responsive insulin represents a promising approach to regulate blood glucose levels. We previously showed that attaching two fluorophenylboronic acid (FPBA) residues to the C-terminal B chain of insulin glargine led to glucose-dependent solubility. Herein, we demonstrated that relocating FPBA from B chain to A chain increased the baseline solubility without affecting its potency. Furthermore, increasing the number of FPBA groups led to increased glucose-dependent solubility., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Lin, Zheng, Purushottam, Zhang and Chou.)

Insulin derivatives such as insulin detemir and insulin degludec are U.S. Food and Drug Administration (FDA)-approved long-acting insulin currently used by millions of people with diabetes. These derivatives are modified in C-terminal B29 lysine to retain insulin bioactivity. New and efficient methods for facile synthesis of insulin derivatives may lead to new discovery of therapeutic insulin. Herein, we report a new method using sortase A (SrtA)-mediated ligation for the synthesis of insulin derivatives with high efficiency and functional group tolerance in the C-terminal B chain. This new insulin molecule (Ins-SA) with an SrtA-recognizing motif can be conjugated to diverse groups with N-terminal oligoglycines to generate new insulin derivatives. We further demonstrated that a new insulin derivative synthesized by this SrtA-mediated ligation shows strong cellular and in vivo bioactivity. This enzymatic method can therefore be used for future insulin design and development., Competing Interests: The authors declare no competing interest., (© 2021 Chinese Pharmaceutical Association and Institute of Materia Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V.)

The transcriptional coregulator OCA-B promotes expression of T cell target genes in cases of repeated antigen exposure, a necessary feature of autoimmunity. We hypothesized that T cell-specific OCA-B deletion and pharmacologic OCA-B inhibition would protect mice from autoimmune diabetes. We developed an Ocab conditional allele and backcrossed it onto a diabetes-prone NOD/ShiLtJ strain background. T cell-specific OCA-B loss protected mice from spontaneous disease. Protection was associated with large reductions in islet CD8+ T cell receptor specificities associated with diabetes pathogenesis. CD4+ clones associated with diabetes were present but associated with anergic phenotypes. The protective effect of OCA-B loss was recapitulated using autoantigen-specific NY8.3 mice but diminished in monoclonal models specific to artificial or neoantigens. Rationally designed membrane-penetrating OCA-B peptide inhibitors normalized glucose levels and reduced T cell infiltration and proinflammatory cytokine expression in newly diabetic NOD mice. Together, the results indicate that OCA-B is a potent autoimmune regulator and a promising target for pharmacologic inhibition., Competing Interests: Disclosures:   D. Tantin reported a patent (62/666,325). No other disclosures were reported., (© 2020 Kim et al.)

Glucagon-like peptide-1 (GLP-1) signaling is an established therapeutic target for type 2 diabetes mellitus (T2DM). We developed a 7-step synthesis of N55, a positive modulator of GLP-1 signaling isolated from fenugreek (Trigonella foenum-graecum) seeds, with 29% overall yield, and we determined the absolute structure of N55 to be N-((3R,4R,5S)-4,5-dimethyl-2-oxotetrahydrofur-3-yl)linoleic amide.

Although insulin analogs have markedly improved glycemic control for people with diabetes, glycemic excursions still cause major health problems and complications. In particular, the narrow therapeutic window of current insulin therapy makes it extremely difficult to maintain normoglycemia without risking severe hypoglycemia. Currently, there are no FDA-approved insulin therapeutics whose bioactivity is regulated by blood glucose levels. This review discusses recent progress on developing glucose-responsive insulin (GRI) bioconjugates without the need of exogenous matrices. Through this approach, tremendous efforts have been made over the years to demonstrate the promise of better glycemic control and reduced risk of hypoglycemia. Last, we discuss future directions of GRI development with a goal to maximize the glucose responsiveness.

Objective: The rapid population aging is now a global issue. The increase in the elderly population will impact the health care industry and health enterprises; various senior needs will promote the growth of the senior health industry. Most senior health studies are focused on the demand side and scarcely on supply. Our study selected quality enterprises focused on aging health and analyzed different strategies to provide excellent quality services to senior health enterprises., Design: We selected 33 quality senior health enterprises in Taiwan and investigated their excellent quality services strategies by face-to-face semi-structured in-depth interviews with CEO and managers of each enterprise in 2013., Setting: A total of 33 senior health enterprises in Taiwan., Participants: Overall, 65 CEOs and managers of 33 enterprises were interviewed individually., Intervention(s): None., Main Outcome Measure(s): Core values and vision, organization structure, quality services provided, strategies for quality services., Results: This study's results indicated four type of value-added strategy models adopted by senior enterprises to offer quality services: (i) residential care and co-residence model, (ii) home care and living in place model, (iii) community e-business experience model and (iv) virtual and physical portable device model. The common part in these four strategy models is that the services provided are elderly centered. These models offer virtual and physical integrations, and also offer total solutions for the elderly and their caregivers. Through investigation of successful strategy models for providing quality services to seniors, we identified opportunities to develop innovative service models and successful characteristics, also policy implications were summarized., Conclusions: The observations from this study will serve as a primary evidenced base for enterprises developing their senior market and, also for promoting the value co-creation possibility through dialogue between customers and those that deliver service., (© The Author 2017. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Objective: With global population aging, great business opportunities are driven by the various needs that the elderly face in everyday living. Internet development makes information spread faster, also allows elderly and their caregivers to more easily access information and actively participate in value co-creation in the services. This study aims to investigate the designs of value co-creation by the supply and demand sides of the senior industry., Design: This study investigated senior industry in Taiwan and analyzed bussiness models of 33 selected successful senior enterprises in 2013. We adopted series field observation, reviews of documentations, analysis of meeting records and in-depth interviews with 65 CEOs and managers., Setting: Thirty-three quality enterprises in senior industry., Participants: Sixty-five CEOs and managers in 33 senior enterprises., Interventions: None., Main Outcome Measures: Value co-creation design, value co-creating process., Results: We constructed a conceptual model that comprehensively describes essential aspects of value co-creation and categorized the value co-creation designs into four types applying for different business models: (i) interaction in experience spaces co-creation design, (ii) on-site interacting co-creation design, (iii) social networking platform co-creation design and (iv) empowering customers co-creation design. Through value co-creation platform design, the senior enterprises have converted the originally passive roles of the elderly and caregivers into active participants in the value co-creation process., Conclusions: The new paradigm of value co-creation designs not only promote innovative development during the interactive process, lead enterprises reveal and meet customers' needs but also increase markets and profits., (© The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: Population ageing is a global issue that affects almost every country. Most ageing researches focused on demand side and studies related to supply side were relatively scarce. This study selected quality enterprises focus on ageing health and analysed their patterns on providing quality services successfully., Design: Our study selected quality senior health enterprises and explored their success patterns through face-to-face semi-structured in-depth interviews with CEO of each enterprise in 2013., Setting: Thirty-three quality senior health enterprises in Taiwan., Participants: Thirty-three CEO's of enterprises were interviewed individually., Intervention: None., Main Outcome Measures: Core values and vision, historical development, organization structure, services/products provided, delivering channels, customer relationships and further development strategies., Results: Our results indicated success patterns for senior enterprises that there were meeting diversified lifestyles and substitutive needs for the elderly and their caregivers, providing a total solution for actual/virtual integration and flexible one-stop shopping services. We classified these enterprises by used degree of clicks-and-mortar of services and residing situation of the elderly. Industry characteristics and policy implications were summarized., Conclusions: Our observations will serve as a primary evidenced base for enterprises developing their senior market, and also for opening dialogue between customers and enterprises to facilitate valuable opportunities for co-creation between the supply and demand sides., (© The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care; all rights reserved.)

The glucagon-like peptide-1 receptor (GLP-1R) is expressed in many tissues and has been implicated in diverse physiological functions, such as energy homeostasis and cognition. GLP-1 analogs are approved for treatment of type 2 diabetes and are undergoing clinical trials for other disorders, including neurodegenerative diseases. GLP-1 analog therapies maintain chronically high plasma levels of the analog and can lead to loss of spatiotemporal control of GLP-1R activation. To avoid adverse effects associated with current therapies, we characterized positive modulators of GLP-1R signaling. We screened extracts from edible plants using an intracellular cAMP biosensor and GLP-1R endocytosis assays. Ethanol extracts from fenugreek seeds enhanced GLP-1 signaling. These seeds have previously been found to reduce glucose and glycated hemoglobin levels in humans. An active compound (N55) with a new N-linoleoyl-2-amino-γ-butyrolactone structure was purified from fenugreek seeds. N55 promoted GLP-1-dependent cAMP production and GLP-1R endocytosis in a dose-dependent and saturable manner. N55 specifically enhanced GLP-1 potency more than 40-fold, but not that of exendin 4, to stimulate cAMP production. In contrast to the current allosteric modulators that bind to GLP-1R, N55 binds to GLP-1 peptide and facilitates trypsin-mediated GLP-1 inactivation. These findings identify a new class of modulators of GLP-1R signaling and suggest that GLP-1 might be a viable target for drug discovery. Our results also highlight a feasible approach for screening bioactive activity of plant extracts., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)

Background/purpose: Drug-eluting stents (DESs) have been shown to reduce in-stent restenosis and target vessel revascularization (TVR) in large clinical trials. We conducted this study to elucidate the differences in the cost and clinical outcome of DESs and bare metal stents (BMSs)., Methods: We retrospectively analyzed the clinical data and costs of patients with stable angina treated with coronary stents from September 2003 to January 2005 at the National Taiwan University Hospital, Taipei, Taiwan., Results: We enrolled 186 patients treated with DESs and 194 patients treated with BMSs. The use of DESs is associated with a lower rate of TVR compared with that with BMSs (12%vs. 22%, p = 0.011). Compared with the BMS group, the overall costs were significantly higher in the DES group (NT$352,495 ± 140,408 vs. NT$298,947 ± 131,289, p<0.001). The incremental cost to avoid one TVR at 2 years was NT$546,444 (95% confidence interval: NT$151,071-2,565,793)., Conclusion: The use of DESs reduces the rate of TVR at 2 years after intervention, but is probably not cost-effective compared with BMSs in patients with stable coronary artery disease., (Copyright © 2011 Formosan Medical Association & Elsevier. Published by Elsevier B.V. All rights reserved.)

An efficient stereoselective synthesis of alpha-(2-->9)-tetrasialic acid was achieved using tri-O-chloroacetyl-derivatized sialyl donor and a triol sialyl acceptor. Both the acceptor and the donor were also protected with a cyclic 5-N-4-O-carbonyl protecting group. The donor is highly reactive and enabled alpha-selective sialylation with various primary, secondary, and tertiary acceptors under in situ activation conditions (NIS/TfOH, -78 degrees C, acetonitrile/dichloromethane). The trans-fused oxazolidinone ring and O-chloroacetyl protecting groups were easily removed under mild reaction conditions to provide the fully deprotected alpha(2-->9)-tetrasialic acid.