Low concentrations (<3.0 mM) of the anionic surfactant sodium dodecyl sulfate (SDS) have been shown to induce the formation of amyloid fibers in more than 20 different mesophile-derived proteins in the cationic state. It is not known whether SDS has similar effects on hyperthermophile-derived proteins, which are otherwise thought to be "ultrastable" and inordinately resistant to structural perturbations at room temperature. Here, we show that low (<4.5 mM) concentrations of SDS rapidly induce the formation of aggregates and amyloid fibers in five different ultrastable Pyrococcus furiosus proteins in the cationic state. We also show that amyloid formation is accompanied by the development of a characteristic, negative circular dichroism band at ∼230 nm. These effects are not seen if the proteins have a net negative charge or when higher concentrations of SDS are used (which induce helix formation instead). Our results appear to reveal a potential weakness or "Achilles' heel" in ultrastable proteins from hyperthermophiles. They also provide very strong support for the view that SDS initially interacts with proteins through electrostatic interactions, and not hydrophobic interactions, eliciting similar effects entirely regardless of protein molecular weight, or structural features such as quaternary structure or tertiary structural stability.
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http://dx.doi.org/10.1021/acs.biochem.5b01343 | DOI Listing |
J Foot Ankle Res
December 2024
Physiotherapy Department, School of Primary and Allied Health Care, Faculty of Medicine Nursing and Health Science, Monash University, Melbourne, Victoria, Australia.
Objectives: Insertional Achilles tendinopathy is a common and disabling condition. This trial aimed to determine the feasibility of conducting a parallel group randomised trial to evaluate the efficacy of heel lifts compared to a sham intervention for reducing pain intensity associated with insertional Achilles tendinopathy.
Methods: Twenty-six people with insertional Achilles tendinopathy were randomised to either the heel lift group or sham intervention group.
Health Econ Rev
December 2024
Department of Medical Administration, First Affiliated Hospital of Hainan Medical University, Haikou, 570102, China.
China's primary healthcare (PHC) system, together with rural healthcare services, remains the Achilles' heel in the national healthcare system. Healthcare workers, specifically village doctors, are an integral part of the healthcare system. Using the two-stage data envelopment analysis (DEA) and Tobit regression analysis, this study aims to investigate the efficiency of healthcare expenditures on medical resources and services in China, as well as determine how different types of healthcare work influence efficiency.
View Article and Find Full Text PDFZhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
December 2024
Senior Department of Orthopedics, the Fourth Medical Center of Chinese PLA General Hospital, Beijing, 100142, P. R. China.
Objective: To explore the difference in effectiveness between a dynamic rehabilitation protocol and a traditional static rehabilitation protocol after the treatment of acute Achilles tendon rupture with channel assisted minimally invasive repair (CAMIR) technique through a prospective comparative trial, aiming to provide a reference for clinically selecting a feasible treatment regimen.
Methods: Patients with acute Achilles tendon rupture admitted between June 2021 and June 2022 were included in the study, with 60 patients meeting the selection criteria. They were randomly divided into a dynamic rehabilitation group ( =30) and a static rehabilitation group ( =30) using a computer-generated random number method.
J Clin Orthop Trauma
December 2024
Chacha Nehru Bal Chikitsalaya, New Delhi, India.
Background: The study aimed to quantify and correlate kinematic coupling linkage of foot abduction (correction of adduction) and inversion, heel varus and ankle equinus for clubfeet corrected by Ponseti technique.
Methods: Measurements of foot abduction (derotation of carpopedal block), heel varus and ankle equinus were available from Dimeglio scores in 25 feet. Radiological angles were considered for foot inversion-eversion.
J Invest Dermatol
December 2024
Translational Skin Cancer Research, German Cancer Consortium (DKTK), University Medicine Essen, Essen, Germany; Deutsches Krebsforschungszentrum, Heidelberg, Germany.
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