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1.
Biomed Rep ; 18(4): 27, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36909940

RESUMO

The multiple endocrine neoplasia type 1 gene coding the protein menin was originally identified in patients with multiple endocrine tumors, and is mainly expressed in the cell nucleus. Multiple lines of evidence have indicated that menin acts as a tumor suppressor protein interacting with other various proteins. The mechanism of menin inhibiting tumorigenesis remains unclear. The present study analyzed the expression of menin and IQ motif-containing GTPase-activating protein 1 (IQGAP1) proteins in gastric cancer tissues and cell lines, and investigated the association between these two molecules. Western blotting was used to determine the quantity of target proteins. Cell proliferation was measured using MTT assay. It was found that the protein expression of menin was lower in gastric cancer tissues and AGS cells, while the protein expression of IQGAP1 was higher, compared with the levels observed in normal tissues and GES-1 cells. Ectopic expression of IQGAP1 stimulated the proliferation of gastric cancer cells, but did not affect the expression of menin. However, overexpression of menin inhibited the proliferation of gastric cancer cells. The inhibition was partly achieved through inhibiting the expression of IQGAP1, which was accompanied by inhibition of PI3K and NF-κB expression. Taken together, the present results suggest a novel function for menin and IQGAP1 contributing to suppress the proliferation of gastric cancer cells.

2.
J Thorac Dis ; 15(2): 365-375, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36910115

RESUMO

Background: The testing for capability of some routine blood test parameters to reflect the biology of non-small cell lung carcinoma with different driver mutations is of great interest and practice significance. We aim to screen these variables and, if allowed, develop a novel predictive model based on results of these routine blood tests commonly performed in clinical practice to inform which can help doctors assess the patient's genetic mutation status as early as possible before surgery. Methods: For the exploration cohort, we included 1,595 patients who were diagnosed with non-small cell lung cancer (NSCLC) and genetically profiled by a next-generation sequencing panel in the First Affiliated Hospital of Guangzhou Medical University. The external validation cohort, which consists of 197 NSCLC cancer patients from Sun Yat-sen University Cancer Hospital, was subsequently established. Results: We analyzed the association between 46 frequently tested laboratory variables and different genetic mutation types. KRAS mutation was found to be a unique subtype that exclusively correlated with several blood parameters in our study. Least absolute shrinkage and selection operator (LASSO) regression was performed, and the following parameters were found to be significantly associated with KRAS mutation: triglycerides [odds ratio (OR) =1.63], arterial oxygen partial pressure (OR =0.97), uric acid (OR =1.01), basophil count (OR =1.41), eosinophil count (OR =1.146), fibrinogen (OR =1.42), standard bicarbonate (OR =0.85), high-density lipoprotein cholesterol (OR =0.18), alpha-L-fucosidase (OR =1.07). The areas under the receiver-operator characteristic curve in the training set and the external validation set were 0.85 [95% confidence interval (CI): 0.81-0.88] and 0.81 (95% CI: 0.71-0.91), respectively. Conclusions: We developed a non-invasive, more cost-effective predictive model of NSCLC based on routinely available variables, with practical predictive power. This model can be used as a practical screening tool to guide the use of more specialized and expensive molecular assays for KRAS mutation in NSCLC. However, further studies are warranted to investigate the mechanism underlying such association between KRAS mutations and the related parameters of blood tests.

3.
J Biomater Sci Polym Ed ; : 1-15, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36938635

RESUMO

Efficient hemorrhage control of severe wound injuries is an urgent medical need, deserving agents with promising blood coagulation and biocompatible characteristics. Current work developed polydopamine (PDA) functionalized porous starch powder (PS-PDA) for emergency bleeding treatment. The micro-morphology and elements, chemical groups, and porosity of PS-PDA were systematically characterized. Its comparison with porous starch (PS) revealed the promising potential of this composite in medical practice. On one hand, PS-PDA showed superior surface area and biomineralization affinity over PS, along with comparable hemo/cyto-compatibility. On the other hand, the photothermal effect of PDA under near Infrared (NIR) light paved the possibility to accelerate blood coagulation in situ. In vivo studies indicated PS-PDA can significantly reduce blood loss and improvement of hemostasis efficiency accompanied by NIR light exposure. These results suggest that this newly developed PS-PDA powder can serve as a promising hemostatic material for bleeding wound control.

4.
Medicine (Baltimore) ; 102(10): e33009, 2023 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-36897698

RESUMO

Obesity is detrimental to general health and also reproductive health. This study aimed to evaluate whether weight reduction in obese infertile women prior to in vitro fertilization reduces the total gonadotropin dose and improves pregnancy outcomes. This retrospective cohort study was performed at the Jiaxing Maternity and Child Health Care Hospital between January 2017 and January 2022, and 197 women were enrolled. The women were divided into 2 groups according to the weight loss goal of 5%: weight reduction group A (≥weight loss goal of 5%) and control group A (

Assuntos
Infertilidade Feminina , Criança , Gravidez , Feminino , Humanos , Estudos Retrospectivos , Fertilização In Vitro , Obesidade , Taxa de Gravidez , Nascido Vivo , Gonadotropinas , Redução de Peso
5.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(2): 380-385, 2023 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-36949702

RESUMO

Objective: To explore the status quo and influencing factors of feeding behaviors of micronutrient powders (MNP), or yingyangbao in Pinyin, the Chinese Romanization system, of baby caregivers in remote rural areas of Sichuan Province. Methods: In 2019, caregivers of babies aged 6 to 24 months from 6 counties of Sichuan Province were selected as the respondents of the survey through a multistage cluster random sampling method. Data concerning the baby caregivers' attitude of behavior, subjective norms, behavioral intention, and feeding behaviors about MNP feeding were collected with a questionnaire through a structured interview. Based on the theory of reasoned action, a structural equation model was constructed to explore the influencing factors of feeding behaviors. Results: A total of 1002 valid samples were included in the study. The effective feeding rate of MNP among the baby caregivers was 55.49%. The results of model analysis suggested that attitude of behavior ( ß direct=0.212, 95% CI: 0.105-0.327), subjective norm ( ß direct=0.123, 95% CI: 0.016-0.228), and behavioral intention ( ß direct=0.162, 95% CI: 0.093-0.224) could have a significant direct impact on MNP feeding behaviors. Behavior attitude ( ß indirect=0.044, 95% CI: 0.023-0.073) and subjective norms ( ß indirect=0.018, 95% CI: 0.001-0.040) could have a significant indirect impact on MNP feeding behaviors through the intermediary of behavioral intention. Among the three theoretical elements, attitude of behavior had the largest total effect on the feeding behavior ( ß total=0.256, 95% CI: 0.148-0.366). Conclusion: The effective feeding rate of MNP among baby caregivers in remote rural areas of Sichuan Province is low. The attitude of behavior and subjective norms of caregivers may have a direct impact on their feeding behavior, and both attitude of behavior and subjective norms can have an indirect impact on the feeding behavior through the intermediary of behavioral intention. The influence of attitude of behavior attitude on feeding behavior is greater than that of subjective norms. Future intervention plans for promoting effective MNP feeding should incorporate health education for baby caregivers and their important social relations. Thus, baby caregivers' attitude and willingness for MNP feeding will be strengthened and the effective feeding rate of MNP will be improved accordingly.


Assuntos
Cuidadores , Micronutrientes , Lactente , Humanos , Pós , Teoria do Comportamento Planejado , Comportamento Alimentar , China
6.
Cell Rep ; 42(4): 112283, 2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36961815

RESUMO

Although touch and itch are coded by distinct neuronal populations, light touch also provokes itch in the presence of exogenous pruritogens, resulting in a phenomenon called alloknesis. However, the cellular and molecular mechanisms underlying the initiation of pruritogen-induced mechanical itch sensitization are poorly understood. Here, we show that intradermal injections of histamine or chloroquine (CQ) provoke alloknesis through activation of TRPV1- and MrgprA3-expressing prurioceptors, and functional ablation of these neurons reverses pruritogen-induced alloknesis. Moreover, genetic ablation of mechanosensitive Piezo2 channel function from MrgprA3-expressing prurioceptors also dampens pruritogen-induced alloknesis. Mechanistically, histamine and CQ sensitize Piezo2 channel function, at least in part, through activation of the phospholipase C (PLC) and protein kinase C-δ (PKCδ) signaling. Collectively, our data find a TRPV1+/MrgprA3+ prurioceptor-Piezo2 signaling axis in the initiation of pruritogen-induced mechanical itch sensitization in the skin.

7.
bioRxiv ; 2023 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-36945415

RESUMO

The SAM/SAH riboswitch binds S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) with similar affinities. Mg 2+ is generally known to stabilize RNA structures by neutralizing phosphates, but how it contributes to ligand binding and conformational transition is understudied. Here, extensive molecular dynamics simulations (totaling 120 µs) identified over 10 inner-shell Mg 2+ ions in the SAM/SAH riboswitch. Six of them line the two sides of a groove to widen it and thereby pre-organize the riboswitch for ligand entry. They also form outer-shell coordination with the ligands and stabilize an RNA-ligand hydrogen bond, which effectively diminish the selectivity between SAM and SAH. One Mg 2+ ion unique to the apo form maintains the Shine-Dalgarno sequence in an autonomous mode and thereby facilitates its release for ribosome binding. Mg 2+ thus plays vital roles in SAM/SAH riboswitch function.

8.
Nat Commun ; 14(1): 1623, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36959168

RESUMO

Kinetics of NMDA receptor (NMDAR) ion channel opening and closing contribute to their unique role in synaptic signaling. Agonist binding generates free energy to open a canonical gate at the M3 helix bundle crossing. Single channel activity is characterized by clusters, or periods of rapid opening and closing, that are separated by long silent periods. A conserved glycine in the outer most transmembrane helices, the M4 helices, regulates NMDAR function. Here we find that the GluN1 glycine mainly regulates single channel events within a cluster, whereas the GluN2 glycine mainly regulates entry and exit from clusters. Molecular dynamics simulations suggest that, whereas the GluN2 M4 (along with GluN2 pre-M1) regulates the gate at the M3 helix bundle crossing, the GluN1 glycine regulates a 'gate' at the M2 loop. Subsequent functional experiments support this interpretation. Thus, the distinct kinetics of NMDARs are mediated by two gates that are under subunit-specific regulation.


Assuntos
N-Metilaspartato , Receptores de N-Metil-D-Aspartato , Receptores de N-Metil-D-Aspartato/química , Ativação do Canal Iônico/fisiologia , Simulação de Dinâmica Molecular , Glicina/metabolismo
9.
Commun Biol ; 6(1): 311, 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36959324

RESUMO

Mtb infects a quarter of the worldwide population. Most drugs for treating tuberculosis target cell growth and division. With rising drug resistance, it becomes ever more urgent to better understand Mtb cell division. This process begins with the formation of the Z-ring via polymerization of FtsZ and anchoring of the Z-ring to the inner membrane. Here we show that the transmembrane protein FtsQ is a potential membrane anchor of the Mtb Z-ring. In the otherwise disordered cytoplasmic region of FtsQ, a 29-residue, Arg/Ala-rich α-helix is formed that interacts with upstream acidic residues in solution and with acidic lipids at the membrane surface. This helix also binds to the GTPase domain of FtsZ, with implications for drug binding and Z-ring formation.


Assuntos
Proteínas de Escherichia coli , Tuberculose , Humanos , Proteínas de Escherichia coli/metabolismo , Escherichia coli/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas do Citoesqueleto/metabolismo , Tuberculose/tratamento farmacológico , Proteínas de Membrana/metabolismo
10.
J Mol Biol ; 435(8): 168035, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36863659

RESUMO

Human WASP and N-WASP are homologous proteins that require the binding of multiple regulators, including the acidic lipid PIP2 and the small GTPase Cdc42, to relieve autoinhibition before they can stimulate the initiation of actin polymerization. Autoinhibition involves intramolecular binding of the C-terminal acidic and central motifs to an upstream basic region and GTPase binding domain. Little is known about how a single intrinsically disordered protein, WASP or N-WASP, binds multiple regulators to achieve full activation. Here we used molecular dynamics simulations to characterize the binding of WASP and N-WASP with PIP2 and Cdc42. In the absence of Cdc42, both WASP and N-WASP strongly associate with PIP2-containing membranes, through their basic region and also possibly through a tail portion of the N-terminal WH1 domain. The basic region also participates in Cdc42 binding, especially for WASP; consequently Cdc42 binding significantly compromises the ability of the basic region in WASP, but not N-WASP, to bind PIP2. PIP2 binding to the WASP basic region is restored only when Cdc42 is prenylated at the C-terminus and tethered to the membrane. This distinction in the activation of WASP and N-WASP may contribute to their different functional roles.

11.
J Chem Phys ; 158(9): 091105, 2023 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-36889962

RESUMO

Allosteric regulation of intrinsically disordered proteins (IDPs) is still vastly understudied compared to the counterpart of structured proteins. Here, we used molecular dynamics simulations to characterize the regulation of the IDP N-WASP by the binding of its basic region with inter- and intramolecular ligands (PIP2 and an acidic motif, respectively). The intramolecular interactions keep N-WASP in an autoinhibited state; PIP2 binding frees the acidic motif for interacting with Arp2/3 and thereby initiating actin polymerization. We show that PIP2 and the acidic motif compete in binding with the basic region. However, even when PIP2 is present at 30% in the membrane, the acidic motif is free of contact with the basic region ("open" state) in only 8.5% of the population. The very C-terminal three residues of the A motif are crucial for Arp2/3 binding; conformations where only the A tail is free are present at a much higher population than the open state (40- to 6-fold, depending on the PIP2 level). Thus, N-WASP is competent for Arp2/3 binding before it is fully freed from autoinhibition.


Assuntos
Actinas , Proteína da Síndrome de Wiskott-Aldrich , Actinas/química , Proteína da Síndrome de Wiskott-Aldrich/metabolismo , Transdução de Sinais , Ligação Proteica
12.
BMC Med ; 21(1): 94, 2023 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-36927541

RESUMO

BACKGROUND: Previous studies have shown that monotherapy with apatinib, an oral tyrosine kinase inhibitor, has promising efficacy for treating recurrent or metastatic (RM) nasopharyngeal carcinoma (NPC) patients. In this study, we aimed to assess the efficacy and safety of apatinib combined with capecitabine as a second-line therapy or beyond for treating RM-NPC patients who failed the first-line platinum-based chemotherapy. METHODS: In this single-arm, phase II study, we enrolled RM-NPC patients who had at least one measurable lesion according to the Response Evaluation Criteria in Solid Tumors (RECIST v1.1). The sample size was determined using Simon's two-stage design. All patients were administered with apatinib 500 mg once daily and capecitabine 1000 mg/m2 twice per day on days 1-14 of each 21-day cycle. The primary endpoint was the objective response rate (ORR), and the secondary endpoints comprised disease control rate (DCR), duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: We enrolled 64 patients from September 2018 to August 2020. The ORR and DCR were 39.1% (95% CI, 27.1-52.1) and 85.9% (95% CI, 75.0-93.4), respectively. The median DoR was 14.4 months (95% CI, 7.8-21.0). As of April 20, 2021, the median follow-up duration was 12.0 months. The median PFS was 7.5 months (95% CI, 5.0-10.0) and the median OS was 15.7 months (95% CI, 11.3-20.1). The most common toxicities of any grade were anemia (75.0%), hand-foot syndrome (65.6%), and proteinuria (64.0%). Grade 3-4 toxicities were observed in 36 (56.3%) patients, with hypertension (14.1%), mucositis (12.4%), and fatigue (10.9%) most commonly observed. CONCLUSIONS: Apatinib plus capecitabine shows promising efficacy as a second-line treatment option in pretreated platinum-refractory RM-NPC patients. Dose selection of this combination needs further investigation considering the toxicity. TRIAL REGISTRATION: Chi-CTR1800017229.


Assuntos
Neoplasias Nasofaríngeas , Humanos , Capecitabina/efeitos adversos , Estudos Prospectivos , Carcinoma Nasofaríngeo/tratamento farmacológico , Neoplasias Nasofaríngeas/tratamento farmacológico
13.
Vaccines (Basel) ; 11(3)2023 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-36992112

RESUMO

The 23-valent pneumococcal vaccine (PPV23) is a classical common vaccine used to prevent pneumococcal disease. In past decades, it was thought that vaccination with this vaccine induces humoral immunity, thereby reducing the disease associated with infection with 23 common serotypes of Streptococcus pneumoniae (Sp). However, for this polysaccharide vaccine, the mechanism of immune response at the transcriptional level has not been fully studied. To identify the lncRNAs (long noncoding RNAs) and mRNAs in spleens related to immunity after PPV23 vaccination in mice, high-throughput RNA sequencing of spleens between a PPV23 treatment group and a control group were performed and evaluated in this study. The RNA-seq results identified a total of 41,321 mRNAs and 34,375 lncRNAs, including 55 significantly differentially expressed (DE) mRNAs and 389 DE lncRNAs (p < 0.05) between the two groups. GO and KEGG annotation analysis indicated that the target genes of DE lncRNAs and DE mRNAs were related to T-cell costimulation, positive regulation of alpha-beta T-cell differentiation, the CD86 biosynthetic process, and the PI3K-Akt signaling pathway, indicating that the polysaccharide component antigens of PPV23 might activate a cellular immune response during the PPV23 immunization process. Moreover, we found that Trim35 (tripartite motif containing 35), a target gene of lncRNA MSTRG.9127, was involved in regulating immunity. Our study provides a catalog of lncRNAs and mRNAs associated with immune cells' proliferation and differentiation, and they deserve further study to deepen the understanding of the biological processes in the regulation of PPV23 during humoral immunity and cellular immunity.

14.
Endocrinol Diabetes Nutr (Engl Ed) ; 70(2): 124-129, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36925229

RESUMO

INTRODUCTION: circRNA LRP6 participates in high-glucose-regulated cellular behaviours, while its role in gestational diabetes mellitus (GDM) is unclear. Our preliminary sequencing analysis revealed the altered expression of LRP6, suggesting its potential involvement in GDM and possible clinical value. This study explored the involvement of LRP6 in GDM. METHODS: In this study, a total of 300 pregnant women were enrolled and followed up until delivery. The occurrence of GDM and adverse outcomes was recorded. These 300 participants were grouped into high and low LRP6 level groups (n=150; cutoff=median). Occurrence of GDM and adverse outcomes were compared between the two groups. ROC curve analysis was conducted to explore the role of LRP6 expression on the day of admission in predicting GDM. Associations between LRP6 expression and adverse outcomes were analysed with the Chi-squared test. RESULTS: We observed that participants in the high LRP6 level group experienced a higher incidence of GDM during follow-up (33/150) compared to those in the low LRP6 level group (10/150). Compared to participants who developed GDM during follow-up, participants who did not develop GDM showed lower expression levels of LRP6 in plasma. ROC curve analysis showed that high expression levels of LRP6 on the day of admission effectively distinguished potential GDM patients from other participants. Interestingly, LRP6 was only closely associated with foetal malformation and intrauterine death, but not premature delivery, hypertension, macrosomia, intrauterine distress, miscarriage and intrauterine infection in all participants. CONCLUSION: Therefore, increased expression levels of LRP6 in GDM predicts foetal malformation and intrauterine death.


Assuntos
Diabetes Gestacional , Doenças do Recém-Nascido , Recém-Nascido , Gravidez , Feminino , Humanos , Resultado da Gravidez , RNA Circular , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade
15.
ArXiv ; 2023 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-36994168

RESUMO

Power law distributions are widely observed in chemical physics, geophysics, biology, and beyond. The independent variable x of these distributions has an obligatory lower bound and in many cases also an upper bound. Estimating these bounds from sample data is notoriously difficult, with a recent method involving O(N^3) operations, where N denotes sample size. Here I develop an approach for estimating the lower and upper bounds that involves O(N) operations. The approach centers on calculating the mean values, x_min and x_max, of the smallest x and the largest x in N-point samples. A fit of x_min or x_max as a function of N yields the estimate for the lower or upper bound. Application to synthetic data demonstrates the accuracy and reliability of this approach.

16.
BMC Musculoskelet Disord ; 24(1): 228, 2023 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973701

RESUMO

BACKGROUND: Trigger thumb is a pathologic condition of the digital pulleys and flexor tendons. To find a cutoff value of the cross-sectional area ratio of specific parts of the flexor pollicis longus tendon to diagnosis trigger thumb in the high-frequency ultrasound examination. METHODS: We evaluated 271 healthy volunteers and 57 patients with clinical diagnosis of trigger thumb. The cross-sectional area of the metacarpophalangeal joint of flexor pollicis longus tendon (C1) and the cross-sectional area of the midpoint of the first metacarpal of flexor pollicis longus tendon (C2) were analyzed. RESULTS: There is no difference between gender, age and left and right hands in the ratio of C1 to C2 (C1/ C2). The mean of C1/ C2 in the healthy thumb was 0.983 ± 0.103, which was significantly smaller in comparison to the diseased thumb (P < 0.05). Based on the receiver operating characteristic curve, we chose the diagnostic cut-off value for the C1/ C2 to be 1.362 and 1.153 in order to differ a trigger thumb from children and adults. CONCLUSIONS: The C1/ C2 of the healthy thumb was relatively stable, with a mean value of 0.983 ± 0.103. The cutoff value of C1/C2 to distinguish healthy thumb from diseased thumb in children and adults were 1.362 and 1.153, respectively.


Assuntos
Ossos Metacarpais , Dedo em Gatilho , Adulto , Criança , Humanos , Tendões/diagnóstico por imagem , Polegar/diagnóstico por imagem , Dedo em Gatilho/diagnóstico por imagem , Ultrassonografia
17.
Int J Infect Dis ; 129: 1-9, 2023 Jan 29.
Artigo em Inglês | MEDLINE | ID: covidwho-2210484

RESUMO

OBJECTIVES: To describe the epidemiological, clinical, and household transmission characteristics of pediatric COVID-19 cases in Shanghai, China. METHODS: Pediatric patients with COVID-19 hospitalized in Shanghai from March-May 2022 were enrolled in this retrospective, multicenter cohort study. The symptoms and the risk factors associated with disease severity were analyzed. RESULTS: In total, 2620 cases (age range, 24 days-17 years) were enrolled in this study. Of these, 1011 (38.6%) were asymptomatic, whereas 1415 (54.0%), 190 (7.3%), and 4 (0.2%) patients developed mild, moderate, and severe illnesses, respectively. Household infection rate was negatively correlated with household vaccination coverage. Children aged 0-3 years, those who are unvaccinated, those with underlying diseases, and overweight/obese children had a higher risk of developing moderate to severe disease than children aged 12-17 years, those who were vaccinated, those without any underlying disease, and those with normal weight, respectively (all P <0.05). A prolonged duration of viral shedding was associated with disease severity, presence of underlying diseases, vaccination status, and younger age (all P <0.05). CONCLUSION: Children aged younger than 3 years who were not eligible for vaccination had a high risk of developing moderate to severe COVID-19 with a prolonged duration of viral shedding. Vaccination could protect children from COVID-19 at the household level.

18.
bioRxiv ; 2023 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-36778236

RESUMO

Dynamics is a crucial link between sequence and function for intrinsically disordered proteins (IDPs). NMR spin relaxation is a powerful technique for characterizing the sequence-dependent backbone dynamics of IDPs. Of particular interest is the 15 N transverse relaxation rate ( R 2 ), which reports on slower dynamics (10s of ns up to 1 µs and beyond). NMR and molecular dynamics (MD) simulations have shown that local interactions and secondary structure formation slow down backbone dynamics and raise R 2 . Elevated R 2 has been suggested to be indicators of propensities of membrane association, liquid-liquid phase separation, and other functional processes. Here we present a sequence-based method, SeqDYN, for predicting R 2 of IDPs. The R 2 value of a residue is expressed as the product of contributing factors from all residues, which attenuate with increasing sequence distance from the central residue. The mathematical model has 21 parameters, representing the correlation length (where the attenuation is at 50%) and the amplitudes of the contributing factors of the 20 types of amino acids. Training on a set of 45 IDPs reveals a correlation length of 5.6 residues, aromatic and long branched aliphatic amino acids and Arg as R 2 promotors whereas Gly and short polar amino acids as R 2 suppressors. The prediction accuracy of SeqDYN is competitive against that of recent MD simulations using IDP-specific force fields. For a structured protein, SeqDYN prediction represents R 2 in the unfolded state. SeqDYN is available as a web server at https://zhougroup-uic.github.io/SeqDYNidp/ for rapid R 2 prediction. Significance Statement: How the sequences of intrinsically disordered proteins (IDPs) code for functions is still an enigma. Dynamics, in particular residue-specific dynamics, holds crucial clues. Enormous efforts have been spent to characterize residue-specific dynamics of IDPs, mainly through NMR spin relaxation experiments. Here we present a sequence-based method, SeqDYN, for predicting residue-specific backbone dynamics of IDPs. SeqDYN employs a mathematical model with 21 parameters and is trained on 45 IDPs. It provides not only rapid, accurate prediction but also insightful physical interpretation of sequence-dependent IDP dynamics.

19.
Angew Chem Int Ed Engl ; 62(13): e202218523, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36722939

RESUMO

The copper-catalyzed enantioselective radical difunctionalization of alkenes from readily available alkyl halides and organophosphorus reagents possessing a P-H bond provides an appealing approach for the synthesis of α-chiral alkyl phosphorus compounds. The major challenge arises from the easy generation of a P-centered radical from the P-H-type reagent and its facile addition to the terminal side of alkenes, leading to reverse chemoselectivity. We herein disclose a radical 1,2-carbophosphonylation of styrenes in a highly chemo- and enantioselective manner. The key to the success lies in not only the implementation of dialkyl phosphites with a strong bond dissociation energy to promote the desired chemoselectivity but also the utilization of an anionic chiral N,N,N-ligand to forge the chiral C(sp3 )-P bond. The developed Cu/N,N,N-ligand catalyst has enriched our library of single-electron transfer catalysts in the enantioselective radical transformations.

20.
BMC Pharmacol Toxicol ; 24(1): 10, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36810140

RESUMO

PURPOSE: The study was aimed at evaluating the bioequivalence and safety of oseltamivir phosphate for suspension, provided by Shenzhen Beimei Pharmaceutical Co. Ltd. and manufactured by Hetero Labs Limited, and the reference product TAMIFLU® in healthy Chinese subjects. METHODS: A single-dose, randomized, two-phase, self-crossed model was adopted. Among 80 healthy subjects, 40 subjects in the fasting group and 40 subjects in the fed group. Subjects in the fasting group were randomized into two sequences according to the proportion of 1:1, each given 75 mg/12.5 mL of Oseltamivir Phosphate for Suspension or TAMIFLU®, and cross-administered after 7 days. Postprandial group is the same as fasting group. RESULTS: The Tmax of TAMIFLU® and Oseltamivir Phosphate for Suspension in the fasting group were 1.50 h and 1.25 h, which in the fed group were both 1.25 h. Geometrically adjusted mean ratios of the PK parameters of Oseltamivir Phosphate for Suspension along with TAMIFLU® under fasting and postprandial conditions were in the range of 80.00-125.00% at the 90% confidence interval (CI). The 90% CI of Cmax, AUC0-t, AUC0-∞ for fasting group and postprandial group were (92.39,106.50), (94.26,100.67), (94.32,100.89) and (93.61,105.83),(95.64,100.19),(96.06,102.66). Among the subjects on medication, a total of 18 subjects reported 27 adverse events, all of which were treatment-emergent adverse events (TEAEs), six of these TEAEs were rated as grade 2 in severity and the rest were as grade 1. The number of TEAEs in the test product and the reference product were 14,13 respectively. CONCLUSION: Two Oseltamivir phosphate for suspensions are safe and bioequivalent.


Assuntos
Jejum , Oseltamivir , Humanos , Equivalência Terapêutica , Suspensões , Estudos Cross-Over , Área Sob a Curva , Voluntários Saudáveis , Fosfatos , Comprimidos
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