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1.
Diagnostics (Basel) ; 14(11)2024 Jun 06.
Article in English | MEDLINE | ID: mdl-38893728

ABSTRACT

BACKGROUND: The lack of a clear answer regarding the efficacy of physiotherapy in the treatment of cubital tunnel syndrome (CuTS) has led to attempts to critically assess the scientific studies conducted to date. MATERIALS AND METHODS: Two databases (MEDLINE via PubMed and PEDro) and Google Scholar were used to search for papers. The inclusion criteria were randomized controlled trials, case series, and case reports that evaluate the effects of physiotherapy in the treatment of patients with CuTS. RESULTS: A total of 18 studies met the eligibility criteria, capturing a total of 425 participants. Seven papers were randomized controlled trials, three more described prospective studies without a control group, and eight papers contained case reports. An analysis of the literature evaluating the effectiveness of various forms of broadly defined physiotherapy indicates that their use can have a beneficial effect in reducing many subjective and objective symptoms and improving function. In the majority of papers included in this review, their authors indicated positive therapeutic effects. Only one randomized controlled trial reported no change following therapy. It can therefore be stated that the results of the research conducted so far are optimistic. However, only 7 of the 18 papers were randomized controlled trials, while 3 were prospective studies, and 8 papers were case studies, in which 23 people with CuTS were studied. CONCLUSIONS: The small number of randomized clinical trials and their considerable heterogeneity do not allow firm conclusions to be drawn about the effectiveness of physiotherapy in the conservative treatment of CuTS.

2.
Nat Cell Biol ; 26(3): 404-420, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38424271

ABSTRACT

γ-Tubulin ring complex (γ-TuRC) is the major microtubule-nucleating factor. After nucleation, microtubules can be released from γ-TuRC and stabilized by other proteins, such as CAMSAPs, but the biochemical cross-talk between minus-end regulation pathways is poorly understood. Here we reconstituted this process in vitro using purified components. We found that all CAMSAPs could bind to the minus ends of γ-TuRC-attached microtubules. CAMSAP2 and CAMSAP3, which decorate and stabilize growing minus ends but not the minus-end tracking protein CAMSAP1, induced microtubule release from γ-TuRC. CDK5RAP2, a γ-TuRC-interactor, and CLASP2, a regulator of microtubule growth, strongly stimulated γ-TuRC-dependent microtubule nucleation, but only CDK5RAP2 suppressed CAMSAP binding to γ-TuRC-anchored minus ends and their release. CDK5RAP2 also improved selectivity of γ-tubulin-containing complexes for 13- rather than 14-protofilament microtubules in microtubule-capping assays. Knockout and overexpression experiments in cells showed that CDK5RAP2 inhibits the formation of CAMSAP2-bound microtubules detached from the microtubule-organizing centre. We conclude that CAMSAPs can release newly nucleated microtubules from γ-TuRC, whereas nucleation-promoting factors can differentially regulate this process.


Subject(s)
Microtubule-Associated Proteins , Tubulin , Tubulin/metabolism , Microtubule-Associated Proteins/genetics , Microtubule-Associated Proteins/metabolism , Microtubules/metabolism , Microtubule-Organizing Center/metabolism , Cytoskeleton/metabolism
3.
Sensors (Basel) ; 23(3)2023 Jan 29.
Article in English | MEDLINE | ID: mdl-36772541

ABSTRACT

Malaria is a life-threatening disease caused by parasites that are transmitted to humans through the bites of infected mosquitoes. The early diagnosis and treatment of malaria are crucial for reducing morbidity and mortality rates, particularly in developing countries where the disease is prevalent. In this article, we present a novel convolutional neural network (CNN) architecture for detecting malaria from blood samples with a 99.68% accuracy. Our method outperforms the existing approaches in terms of both accuracy and speed, making it a promising tool for malaria diagnosis in resource-limited settings. The CNN was trained on a large dataset of blood smears and was able to accurately classify infected and uninfected samples with high sensitivity and specificity. Additionally, we present an analysis of model performance on different subtypes of malaria and discuss the implications of our findings for the use of deep learning in infectious disease diagnosis.


Subject(s)
Deep Learning , Humans , Neural Networks, Computer , Diagnosis, Computer-Assisted/methods , Early Diagnosis
4.
J Cell Biol ; 222(3)2023 03 06.
Article in English | MEDLINE | ID: mdl-36695784

ABSTRACT

The γ-tubulin ring complex (γ-TuRC) has essential roles in centrosomal and non-centrosomal microtubule organization during vertebrate mitosis. While there have been important advances in understanding γ-TuRC-dependent microtubule nucleation, γ-TuRC capping of microtubule minus-ends remains poorly characterized. Here, we utilized biochemical reconstitutions and cellular assays to characterize the human γ-TuRC's capping activity. Single filament assays showed that the γ-TuRC remained associated with a nucleated microtubule for tens of minutes. In contrast, caps at dynamic microtubule minus-ends displayed lifetimes of ∼1 min. Reconstituted γ-TuRCs with nucleotide-binding deficient γ-tubulin (γ-tubulinΔGTP) formed ring-shaped complexes that did not nucleate microtubules but capped microtubule minus-ends with lifetimes similar to those measured for wild-type complexes. In dividing cells, microtubule regrowth assays revealed that while knockdown of γ-tubulin suppressed non-centrosomal microtubule formation, add-back of γ-tubulinΔGTP could substantially restore this process. Our results suggest that γ-TuRC capping is a nucleotide-binding-independent activity that plays a role in non-centrosomal microtubule organization during cell division.


Subject(s)
Microtubule-Associated Proteins , Tubulin , Humans , Tubulin/chemistry , Microtubule-Associated Proteins/genetics , Microtubules/chemistry , Microtubule-Organizing Center , Cell Division
5.
Public Health Ethics ; 16(3): 219-231, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38333766

ABSTRACT

Mobile health (mHealth) technologies for self-monitoring health-relevant parameters such as heart frequency, sleeping patterns or exercise regimes aim at fostering healthy behavior change and increasing the individual users to promote and maintain their health. We argue that this aspect of mHealth supports healthism, the increasing shift from institutional responsibility for public health toward individual engagement in maintaining health as well as mitigating health risks. Moreover, this healthist paradigm leads to a shift from understanding health as the absence of illness to regarding health as the performance of certain rituals in order to project healthiness. By drawing from the analogy between healthiness and traditional virtues, we evaluate the promises made by proponents of mHealth technologies for self-monitoring. We argue that the implementation and use of mHealth risk entrenching existing inequalities and, more particularly, tend to exclude populations situated at the losing end of those inequalities from participating in the quasi-virtue of healthiness. Consequently, the implementation and use of mHealth technologies not only present challenges for social justice but also undermine their primary societal goal-to promote public health. Finally, we offer several suggestions on how to realize the potential benefit of mHealth.

6.
Sci Eng Ethics ; 28(3): 29, 2022 06 15.
Article in English | MEDLINE | ID: mdl-35705883

ABSTRACT

This paper analyzes the ethics of social science research (SSR) employing big data. We begin by highlighting the research gap found on the intersection between big data ethics, SSR and research ethics. We then discuss three aspects of big data SSR which make it warrant special attention from a research ethics angle: (1) the interpretative character of both SSR and big data, (2) complexities of anticipating and managing risks in publication and reuse of big data SSR, and (3) the paucity of regulatory oversight and ethical recommendations on protecting individual subjects as well as societies when conducting big data SSR. Against this backdrop, we propose using David Resnik's research ethics framework to analyze some of the most pressing ethical issues of big data SSR. Focusing on the principles of honesty, carefulness, openness, efficiency, respect for subjects, and social responsibility, we discuss three clusters of ethical issues: those related to methodological biases and personal prejudices, those connected to risks arising from data availability and reuse, and those leading to individual and social harms. Finally, we advance considerations to observe in developing future ethical guidelines about big data SSR.


Subject(s)
Big Data , Ethics, Research , Humans , Social Responsibility , Social Sciences
7.
J Cell Biol ; 220(3)2021 03 01.
Article in English | MEDLINE | ID: mdl-33496729

ABSTRACT

The formation of cellular microtubule networks is regulated by the γ-tubulin ring complex (γ-TuRC). This ∼2.3 MD assembly of >31 proteins includes γ-tubulin and GCP2-6, as well as MZT1 and an actin-like protein in a "lumenal bridge" (LB). The challenge of reconstituting the γ-TuRC has limited dissections of its assembly and function. Here, we report a biochemical reconstitution of the human γ-TuRC (γ-TuRC-GFP) as a ∼35 S complex that nucleates microtubules in vitro. In addition, we generate a subcomplex, γ-TuRCΔLB-GFP, which lacks MZT1 and actin. We show that γ-TuRCΔLB-GFP nucleates microtubules in a guanine nucleotide-dependent manner and with similar efficiency as the holocomplex. Electron microscopy reveals that γ-TuRC-GFP resembles the native γ-TuRC architecture, while γ-TuRCΔLB-GFP adopts a partial cone shape presenting only 8-10 γ-tubulin subunits and lacks a well-ordered lumenal bridge. Our results show that the γ-TuRC can be reconstituted using a limited set of proteins and suggest that the LB facilitates the self-assembly of regulatory interfaces around a microtubule-nucleating "core" in the holocomplex.


Subject(s)
Tubulin/metabolism , Actins/metabolism , Green Fluorescent Proteins/metabolism , Humans , Kinetics , Microtubules/metabolism , Recombinant Proteins/isolation & purification , Recombinant Proteins/metabolism , Tubulin/chemistry , Tubulin/ultrastructure
8.
PLoS One ; 15(12): e0243189, 2020.
Article in English | MEDLINE | ID: mdl-33332363

ABSTRACT

Since the epidemic outbreak in early months of 2020 the spread of COVID-19 has grown rapidly in most countries and regions across the World. Because of that, SARS-CoV-2 was declared as a Public Health Emergency of International Concern (PHEIC) on January 30, 2020, by The World Health Organization (WHO). That's why many scientists are working on new methods to reduce further growth of new cases and, by intelligent patients allocation, reduce number of patients per doctor, what can lead to more successful treatments. However to properly manage the COVID-19 spread there is a need for real-time prediction models which can reliably support various decisions both at national and international level. The problem in developing such system is the lack of general knowledge how the virus spreads and what would be the number of cases each day. Therefore prediction model must be able to conclude the situation from past data in the way that results will show a future trend and will possibly closely relate to the real numbers. In our opinion Artificial Intelligence gives a possibility to do it. In this article we present a model which can work as a part of an online system as a real-time predictor to help in estimation of COVID-19 spread. This prediction model is developed using Artificial Neural Networks (ANN) to estimate the future situation by the use of geo-location and numerical data from past 2 weeks. The results of our model are confirmed by comparing them with real data and, during our research the model was correctly predicting the trend and very closely matching the numbers of new cases in each day.


Subject(s)
COVID-19/epidemiology , Models, Biological , Neural Networks, Computer , SARS-CoV-2 , COVID-19/transmission , Humans , Predictive Value of Tests
9.
STAR Protoc ; 1(1)2020 06 19.
Article in English | MEDLINE | ID: mdl-32783031

ABSTRACT

α/ß-tubulin heterodimers, which can harbor diverse isotypes and post-translational modifications, polymerize into microtubules that are fundamental to many cellular processes. Due to long-standing challenges in generating recombinant tubulin, however, it has been difficult to examine the properties of specific tubulin isotypes. Here, we provide a protocol for purifying milligrams of affinity tag-free, isotypically pure recombinant tubulin. Our method can be applicable to any tubulin of interest, opening the door to dissecting how tubulin diversity regulates microtubule function. For complete details on the use and execution of this protocol, please see Ti et al. (2018).


Subject(s)
Cloning, Molecular/methods , Tubulin/isolation & purification , Animals , Humans , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Sf9 Cells , Tubulin/genetics
10.
Chaos Solitons Fractals ; 140: 110203, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32834663

ABSTRACT

Virus spread prediction is very important to actively plan actions. Viruses are unfortunately not easy to control, since speed and reach of spread depends on many factors from environmental to social ones. In this article we present research results on developing Neural Network model for COVID-19 spread prediction. Our predictor is based on classic approach with deep architecture which learns by using NAdam training model. For the training we have used official data from governmental and open repositories. Results of prediction are done for countries but also regions to provide possibly wide spectrum of values about predicted COVID-19 spread. Results of the proposed model show high accuracy, which in some cases reaches above 99%.

11.
Cell Rep ; 31(13): 107791, 2020 06 30.
Article in English | MEDLINE | ID: mdl-32610146

ABSTRACT

Microtubule organization depends on the γ-tubulin ring complex (γ-TuRC), a ∼2.3-MDa nucleation factor comprising an asymmetric assembly of γ-tubulin and GCP2-GCP6. However, it is currently unclear how the γ-TuRC-associated microproteins MZT1 and MZT2 contribute to the structure and regulation of the holocomplex. Here, we report cryo-EM structures of MZT1 and MZT2 in the context of the native human γ-TuRC. MZT1 forms two subcomplexes with the N-terminal α-helical domains of GCP3 or GCP6 (GCP-NHDs) within the γ-TuRC "lumenal bridge." We determine the X-ray structure of recombinant MZT1/GCP6-NHD and find it is similar to that within the native γ-TuRC. We identify two additional MZT/GCP-NHD-like subcomplexes, one of which is located on the outer face of the γ-TuRC and comprises MZT2 and GCP2-NHD in complex with a centrosomin motif 1 (CM1)-containing peptide. Our data reveal how MZT1 and MZT2 establish multi-faceted, structurally mimetic "modules" that can expand structural and regulatory interfaces in the γ-TuRC.


Subject(s)
Microtubule-Associated Proteins/metabolism , Multiprotein Complexes/metabolism , Tubulin/metabolism , HeLa Cells , Humans , Microtubule-Associated Proteins/chemistry , Models, Molecular , Multiprotein Complexes/ultrastructure , Peptides/metabolism , Protein Binding , Protein Multimerization , Protein Structure, Secondary , Tubulin/chemistry , Tubulin/ultrastructure
12.
Cell ; 180(1): 165-175.e16, 2020 01 09.
Article in English | MEDLINE | ID: mdl-31862189

ABSTRACT

The γ-tubulin ring complex (γ-TuRC) is an essential regulator of centrosomal and acentrosomal microtubule formation, yet its structure is not known. Here, we present a cryo-EM reconstruction of the native human γ-TuRC at ∼3.8 Å resolution, revealing an asymmetric, cone-shaped structure. Pseudo-atomic models indicate that GCP4, GCP5, and GCP6 form distinct Y-shaped assemblies that structurally mimic GCP2/GCP3 subcomplexes distal to the γ-TuRC "seam." We also identify an unanticipated structural bridge that includes an actin-like protein and spans the γ-TuRC lumen. Despite its asymmetric architecture, the γ-TuRC arranges γ-tubulins into a helical geometry poised to nucleate microtubules. Diversity in the γ-TuRC subunits introduces large (>100,000 Å2) surfaces in the complex that allow for interactions with different regulatory factors. The observed compositional complexity of the γ-TuRC could self-regulate its assembly into a cone-shaped structure to control microtubule formation across diverse contexts, e.g., within biological condensates or alongside existing filaments.


Subject(s)
Microtubule-Organizing Center/metabolism , Microtubule-Organizing Center/ultrastructure , Tubulin/ultrastructure , Actins/metabolism , Cryoelectron Microscopy/methods , HeLa Cells , Humans , Microtubule-Associated Proteins/metabolism , Microtubule-Associated Proteins/ultrastructure , Microtubules/metabolism , Tubulin/metabolism
13.
Sci Transl Med ; 8(365): 365ra159, 2016 11 16.
Article in English | MEDLINE | ID: mdl-27856798

ABSTRACT

Microtubule-targeting agents (MTAs) are widely used anticancer agents, but toxicities such as neuropathy limit their clinical use. MTAs bind to and alter the stability of microtubules, causing cell death in mitosis. We describe DZ-2384, a preclinical compound that exhibits potent antitumor activity in models of multiple cancer types. It has an unusually high safety margin and lacks neurotoxicity in rats at effective plasma concentrations. DZ-2384 binds the vinca domain of tubulin in a distinct way, imparting structurally and functionally different effects on microtubule dynamics compared to other vinca-binding compounds. X-ray crystallography and electron microscopy studies demonstrate that DZ-2384 causes straightening of curved protofilaments, an effect proposed to favor polymerization of tubulin. Both DZ-2384 and the vinca alkaloid vinorelbine inhibit microtubule growth rate; however, DZ-2384 increases the rescue frequency and preserves the microtubule network in nonmitotic cells and in primary neurons. This differential modulation of tubulin results in a potent MTA therapeutic with enhanced safety.


Subject(s)
Antineoplastic Agents/pharmacology , Lactams, Macrocyclic/pharmacology , Microtubules/drug effects , Neurons/drug effects , Oxazoles/pharmacology , Vinca Alkaloids/pharmacology , Animals , Antineoplastic Agents/chemistry , Cell Line, Tumor , Crystallography, X-Ray , Dimerization , Genomics , Humans , Lactams, Macrocyclic/chemistry , Mice , Microscopy, Electron , Mitosis , Neoplasm Transplantation , Oxazoles/chemistry , Tubulin/chemistry , Vinblastine/analogs & derivatives , Vinblastine/chemistry , Vinblastine/pharmacology , Vinca Alkaloids/chemistry , Vinorelbine
14.
Biol Open ; 5(8): 1040-51, 2016 Aug 15.
Article in English | MEDLINE | ID: mdl-27422905

ABSTRACT

The centrosome-associated proteins Ninein (Nin) and Ninein-like protein (Nlp) play significant roles in microtubule stability, nucleation and anchoring at the centrosome in mammalian cells. Here, we investigate Blastoderm specific gene 25D (Bsg25D), which encodes the only Drosophila protein that is closely related to Nin and Nlp. In early embryos, we find that Bsg25D mRNA and Bsg25D protein are closely associated with centrosomes and astral microtubules. We show that sequences within the coding region and 3'UTR of Bsg25D mRNAs are important for proper localization of this transcript in oogenesis and embryogenesis. Ectopic expression of eGFP-Bsg25D from an unlocalized mRNA disrupts microtubule polarity in mid-oogenesis and compromises the distribution of the axis polarity determinant Gurken. Using total internal reflection fluorescence microscopy, we show that an N-terminal fragment of Bsg25D can bind microtubules in vitro and can move along them, predominantly toward minus-ends. While flies homozygous for a Bsg25D null mutation are viable and fertile, 70% of embryos lacking maternal and zygotic Bsg25D do not hatch and exhibit chromosome segregation defects, as well as detachment of centrosomes from mitotic spindles. We conclude that Bsg25D is a centrosomal protein that, while dispensable for viability, nevertheless helps ensure the integrity of mitotic divisions in Drosophila.

15.
Nat Cell Biol ; 17(7): 907-16, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26098575

ABSTRACT

Microtubules are born and reborn continuously, even during quiescence. These polymers are nucleated from templates, namely γ-tubulin ring complexes (γ-TuRCs) and severed microtubule ends. Using single-molecule biophysics, we show that nucleation from γ-TuRCs, axonemes and seed microtubules requires tubulin concentrations that lie well above the critical concentration. We measured considerable time lags between the arrival of tubulin and the onset of steady-state elongation. Microtubule-associated proteins (MAPs) alter these time lags. Catastrophe factors (MCAK and EB1) inhibited nucleation, whereas a polymerase (XMAP215) and an anti-catastrophe factor (TPX2) promoted nucleation. We observed similar phenomena in cells. We conclude that GTP hydrolysis inhibits microtubule nucleation by destabilizing the nascent plus ends required for persistent elongation. Our results explain how MAPs establish the spatial and temporal profile of microtubule nucleation.


Subject(s)
Microtubule-Associated Proteins/metabolism , Microtubules/metabolism , Tubulin/metabolism , Animals , Axoneme/metabolism , CHO Cells , Cell Line, Tumor , Centrosome/metabolism , Cricetinae , Cricetulus , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Guanosine Triphosphate/analogs & derivatives , Guanosine Triphosphate/metabolism , Humans , Hydrolysis , Immunoblotting , Kinetics , LLC-PK1 Cells , Microscopy, Electron , Microscopy, Fluorescence/methods , Microtubule-Associated Proteins/genetics , Microtubules/drug effects , Microtubules/ultrastructure , Nocodazole/pharmacology , Polymerization/drug effects , Swine , Tubulin Modulators/pharmacology
16.
PLoS One ; 9(2): e86786, 2014.
Article in English | MEDLINE | ID: mdl-24498282

ABSTRACT

Aurora-B is the kinase subunit of the Chromosome Passenger Complex (CPC), a key regulator of mitotic progression that corrects improper kinetochore attachments and establishes the spindle midzone. Recent work has demonstrated that the CPC is a microtubule-associated protein complex and that microtubules are able to activate the CPC by contributing to Aurora-B auto-phosphorylation in trans. Aurora-B activation is thought to occur when the local concentration of Aurora-B is high, as occurs when Aurora-B is enriched at centromeres. It is not clear, however, whether distributed binding to large structures such as microtubules would increase the local concentration of Aurora-B. Here we show that microtubules accelerate the kinase activity of Aurora-B by a "reduction in dimensionality." We find that microtubules increase the kinase activity of Aurora-B toward microtubule-associated substrates while reducing the phosphorylation levels of substrates not associated to microtubules. Using the single molecule assay for microtubule-associated proteins, we show that a minimal CPC construct binds to microtubules and diffuses in a one-dimensional (1D) random walk. The binding of Aurora-B to microtubules is salt-dependent and requires the C-terminal tails of tubulin, indicating that the interaction is electrostatic. We show that the rate of Aurora-B auto-activation is faster with increasing concentrations of microtubules. Finally, we demonstrate that microtubules lose their ability to stimulate Aurora-B when their C-terminal tails are removed by proteolysis. We propose a model in which microtubules act as scaffolds for the enzymatic activity of Aurora-B. The scaffolding activity of microtubules enables rapid Aurora-B activation and efficient phosphorylation of microtubule-associated substrates.


Subject(s)
Aurora Kinase B/metabolism , Centromere/metabolism , Microtubules/metabolism , Xenopus Proteins/metabolism , Animals , Aurora Kinase B/chemistry , Aurora Kinase B/genetics , Chromosomal Proteins, Non-Histone/genetics , Chromosomal Proteins, Non-Histone/metabolism , Electrophoresis, Polyacrylamide Gel , Enzyme Activation , Kinetics , Microtubules/chemistry , Models, Biological , Models, Molecular , Phosphorylation , Protein Binding , Protein Structure, Tertiary , Substrate Specificity , Xenopus Proteins/chemistry , Xenopus Proteins/genetics , Xenopus laevis/genetics , Xenopus laevis/metabolism
17.
Methods Mol Biol ; 777: 167-76, 2011.
Article in English | MEDLINE | ID: mdl-21773928

ABSTRACT

The direct observation of single kinesins and microtubule-associated proteins (MAPs) has become a core tool for cytoskeleton research. We outline several variations to the core experiment that allow the researcher to explore structural and biophysical mechanisms underlying kinesin motility and MAP function.


Subject(s)
Kinesins/chemistry , Microtubule-Associated Proteins/chemistry , Kinesins/metabolism , Microscopy, Fluorescence , Microtubule-Associated Proteins/metabolism
18.
J Chem Inf Model ; 50(12): 2213-20, 2010 Dec 27.
Article in English | MEDLINE | ID: mdl-21090591

ABSTRACT

Although the α-helical secondary structure of proteins is well-defined, the exact causes and structures of helical kinks are not. This is especially important for transmembrane (TM) helices of integral membrane proteins, many of which contain kinks providing functional diversity despite predominantly helical structure. We have developed a Monte Carlo method based algorithm, MC-HELAN, to determine helical axes alongside positions and angles of helical kinks. Analysis of all nonredundant high-resolution α-helical membrane protein structures (842 TM helices from 205 polypeptide chains) revealed kinks in 64% of TM helices, demonstrating that a significantly greater proportion of TM helices are kinked than those indicated by previous analyses. The residue proline is over-represented by a factor >5 if it is two or three residues C-terminal to a bend. Prolines also cause kinks with larger kink angles than other residues. However, only 33% of TM kinks are in proximity to a proline. Machine learning techniques were used to test for sequence-based predictors of kinks. Although kinks are somewhat predicted by sequence, kink formation appears to be driven predominantly by other factors. This study provides an improved view of the prevalence and architecture of kinks in helical membrane proteins and highlights the fundamental inaccuracy of the typical topological depiction of helical membrane proteins as series of ideal helices.


Subject(s)
Algorithms , Computational Biology/methods , Membrane Proteins/chemistry , Databases, Protein , Internet , Models, Molecular , Protein Structure, Secondary
19.
Chem Biol ; 17(9): 970-80, 2010 Sep 24.
Article in English | MEDLINE | ID: mdl-20851346

ABSTRACT

The structure and function of the synthetic innate defense regulator peptide 1018 was investigated. This 12 residue synthetic peptide derived by substantial modification of the bovine cathelicidin bactenecin has enhanced innate immune regulatory and moderate direct antibacterial activities. The solution state NMR structure of 1018 in zwitterionic dodecyl phosphocholine (DPC) micelles indicated an α-helical conformation, while secondary structures, based on circular dichroism measurements, in anionic sodium dodecyl sulfate (SDS) and phospholipid vesicles (POPC/PG in a 1:1 molar ratio) and simulations revealed that 1018 can adopt a variety of folds, tailored to its different functions. The structural data are discussed in light of the ability of 1018 to potently induce chemokine responses, suppress the LPS-induced TNF-α response, and directly kill both Gram-positive and Gram-negative bacteria.


Subject(s)
Anti-Bacterial Agents/chemistry , Antimicrobial Cationic Peptides/chemistry , Immunologic Factors/chemistry , Peptides/chemistry , Amino Acid Sequence , Animals , Anti-Bacterial Agents/pharmacology , Antimicrobial Cationic Peptides/pharmacology , Cattle , Circular Dichroism , Gram-Negative Bacteria/drug effects , Gram-Positive Bacteria/drug effects , Humans , Immunity, Innate/drug effects , Immunologic Factors/pharmacology , Micelles , Microbial Sensitivity Tests , Peptides, Cyclic/chemistry , Phosphorylcholine/analogs & derivatives , Phosphorylcholine/chemistry , Protein Structure, Secondary , Quantitative Structure-Activity Relationship , Sodium Dodecyl Sulfate/chemistry , Tumor Necrosis Factor-alpha/metabolism
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