scholarly journals Exploring the Conformational Transition Between the Fully Folded and Locally Unfolded Substates of the Escherichia coli thiol peroxidase

2019 ◽  
Author(s):  
Diego S. Vazquez ◽  
Ari Zeida ◽  
William A. Agudelo ◽  
Mónica Montes ◽  
Gerardo Ferrer-Sueta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Disulfide Bond ◽  
Conformational Transition ◽  
Single Point ◽  
Sampling Technique ◽  
Conformational Sampling ◽  
Sulfenic Acid ◽  
Dynamic Simulations ◽  
Long Time ◽  
Thiol Peroxidase

AbstractThiol peroxidase from Escherichia coli (EcTPx) is a peroxiredoxin that catalyzes the reduction of different hydroperoxides. During the catalytic cycle of EcTPx, the peroxidatic cysteine (CP) is oxidized to a sulfenic acid by peroxide, then the resolving cysteine (CR) condenses with the sulfenic acid of CP to form a disulfide bond, which is finally reduced by thioredoxin. Purified EcTPx as dithiol and disulfide behaves as a monomer in close to physiological conditions. Although secondary structure rearrangements are present when comparing different redox states of the enzyme, no significant differences in unfolding free energies are observed under reducing and oxidizing conditions. A conformational change denominated fully folded (FF) to locally unfolded (LU) transition, involving a partial unfolding of αH2 and αH3 helices, must occur to enable the formation of the disulfide bond since the catalytic cysteines are 12 Å apart in the FF conformation of EcTPx. To explore this crucial process, the mechanism of the FF→LU and the LU→FF transitions were studied using long time scale conventional molecular dynamic simulations and an enhanced conformational sampling technique for different oxidation and protonation states of CP and/or CR. Our results suggest that the FF→LU transition has a higher associated energy barrier than the refolding LU→FF process in agreement with the relatively slow experimental turnover number of EcTPx. Furthermore, in silico designed single-point mutants of the αH3 enhanced locally unfolding events, suggesting that the native FF interactions in the active site are not evolutionary optimized to fully speed-up the conformational transition of wild-type EcTPx.

scholarly journals Exploring the conformational transition between the fully folded and locally unfolded substates of Escherichia coli thiol peroxidase

2020 ◽  
Vol 22 (17) ◽  
pp. 9518-9533
Author(s):  
Diego S. Vazquez ◽  
Ari Zeida ◽  
William A. Agudelo ◽  
Mónica R. Montes ◽  
Gerardo Ferrer-Sueta ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Conformational Transition ◽  
Accelerated Molecular Dynamics ◽  
Thiol Peroxidase ◽  
Dynamics Simulations ◽  
Conformational Substate

Temporal acquisition of the fully folded conformational substate of the Escherichia coli thiol peroxidase by accelerated molecular dynamics simulations.

scholarly journals Impact of Deuteration and Temperature on Furan Ring Dynamics

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2889
Author(s):  
Przemyslaw Dopieralski ◽  
Iryna V. Omelchenko ◽  
Zdzislaw Latajka
Keyword(s):  
Conformational Changes ◽  
Furan Ring ◽  
Computational Studies ◽  
Significant Progress ◽  
Dynamic Simulations ◽  
Cyclic Molecules ◽  
Ring Dynamics ◽  
Different Temperatures ◽  
Long Time ◽  
Shape And Size

Despite significant progress in conformational analysis of cyclic molecules, the number of computational studies is still limited while most of that available in the literature data have been obtained long time ago with outdated methods. In present research, we have studied temperature driven conformational changes of the furan ring at three different temperatures. Additionally, the effect of deuteration on the ring dynamics is discussed; in addition, the aromaticity indices following the Bird and HOMA schemes are computed along all trajectories. Our ab initio molecular dynamic simulations revealed that deuteration has changed the furan ring dynamics and the obvious consequences; in addition, the shape and size of molecule are expected to be different.

HUBUNGAN PENGGUNAAN GADGET DENGAN PROKRASTINASI AKADEMIK PADA MAHASISWA NERS TINGKAT II STIKes SANTA ELISABETH MEDAN TAHUN 2019

2019 ◽  
Vol 4 (2) ◽  
pp. 89-101
Author(s):  
Samfriati S ◽  
Lilis N ◽  
Mercy N G
Keyword(s):  
Nursing Students ◽  
Sampling Technique ◽  
P Value ◽  
Academic Procrastination ◽  
Cross Sectional ◽  
Exact Test ◽  
Level Ii ◽  
Questionnaire Result ◽  
Long Time ◽  
High Level

Academic procrastination is one of the postponement behaviors in lecture activities that are often found in students, in this study respondents experiencees a high level of procrastination that could hamper academic activities. One of the causes of procrastination is the use of gadgets that are too long to play games, music, entertainment and so on. Goals : The purpose of this study is to find out the relationship between the use of gadgets and academic procrastination onNursing Students level II Saint Elisabeth Medan 2019. Method : The study design is Cross Sectional. Total sampling technique sample are112 students. The measuring instrument used is a questionnaire. Result : The results shows that the majority of use of positive gadgets (92.9%) and moderate academic procrastination (63.4%). Based on the Fisher's Exact Test, it obtained p-value 0.026 (p <0.05), thus indicating a relationship between the use of gadgets and academic procrastination on nursing students level II STIKes Saint Elisabeth Medan. Conculsion: It is expected that respondents will be able to manage time well and not use gadgets for a long time for things that are not useful. Respondent s are expected to use gadgets for things that can support learning activities.

scholarly journals PENGARUH LITERASI KEUANGAN, PENDAPATAN SERTA MASA BEKERJA TERHADAP PERILAKU KEPUTUSAN INVESTASI

2018 ◽  
pp. 1867 ◽  
Author(s):  
IGA MERTHA DEWI ◽  
Ida Bagus Anom Purbawangsa
Keyword(s):  
Financial Literacy ◽  
Investment Decision ◽  
Linear Regression Analysis ◽  
Sampling Technique ◽  
Multiple Linear Regression Analysis ◽  
Decision Behavior ◽  
Financial Conditions ◽  
New Employee ◽  
Long Time ◽  
Positive Effect

Research respondents are employees of PT Bank Pembangunan Daerah Bali Branch Renon with a sample of 76 people. Sampling technique in this research use random sampling. Data were analyzed by using Multiple Linear Regression Analysis. The result of this indicate that financial literacy, income has a positive effect on investment decision behavior, but the work period positively has no effect on investment decision behavior. This is because in the banking industry, the entire new employee and who have been working long time get the training and obtain informations about financial developments and financial conditions that occur at this time. In the other words the undertanding of financial literacy and employee behavior is almost the same. Based on the results of statistical data, financial literacy variables have the most influence in determining the behavior of investment decisions compared to income. This explains that a good understanding of finance is a major factor in determining an invesment decisions.

In vivo formation of Cu,Zn superoxide dismutase disulfide bond in Escherichia coli

FEBS Letters ◽  
1999 ◽  
Vol 443 (3) ◽  
pp. 313-316 ◽  
Author(s):  
Andrea Battistoni ◽  
Anna Paola Mazzetti ◽  
Giuseppe Rotilio
Keyword(s):  
Escherichia Coli ◽  
Superoxide Dismutase ◽  
Disulfide Bond

scholarly journals USIA DAN BUDAYA PANTANGMAKANAN MEMPENGARUHI PENYEMBUHAN LUKA PERINEUM PADA IBU NIFAS HARI KE 7

2015 ◽  
Vol 6 (2) ◽  
Author(s):  
Sondang Sidabutar
Keyword(s):  
Wound Healing ◽  
Wound Care ◽  
Healing Process ◽  
Sampling Technique ◽  
Perineal Wound ◽  
Wound Healing Process ◽  
Birth Canal ◽  
Perineal Wound Healing ◽  
Health Officer ◽  
Long Time

Wound healing is a long time in there covery process because of damage to the skin or skin tissue disintegritas. According to Rustam Mochtar(1998), the injured in the birth canal when not accompanied by infection will heal within6-7days. Based on the results of a survey on BPS Ny. Arifin S. Surabaya, from as many as7 of 10 respondents (70%) found the wound is still wet. The purpose of this study was to determine age and cultural picture of incontinence on postpartum mother's perineal wound healing on the seventh day in the BPS Ny. Arifin S. Surabaya. In this research using descriptive method with the study population was all mothers with post natal on the seventh day stit chesin the perineum which controls BPS Ny. Arifin S. Surabaya period from July to August 2008 as many as 49 people. Sampling of non-probability sampling with a sampling technique is saturated. By using questionnaires and observation sheets as research instruments. Data created frequency tables and cross tabulations and then summed. Based on the results of research on maternal postnatal day 9 to 7, obtained the majority of postnatal mother saged <35 years of the perineal wound healed as many as 24 people (66.66%) and in postpartum mothers who do not abstain from the majority of the perineal wound healed as many as17 people (77.27%). By looking at these result it can be concluded that the perineal wound healing can be influenced byculture age and abstinence from food. Therefore, the provision of good information and right by the health officer of the perineal wound care will affect the success of the perineal wound healing process.

scholarly journals Comparative study on lesions of reproductive disorders of cows and female dromedary camels slaughtered at Addis Ababa, Adama and Akaki abbatoirs with bacterial isolation and characterization

2020 ◽  
Author(s):  
Aynalem Mandefro ◽  
Tilaye Demissie Ayana ◽  
Gemechu Chala Hunderra ◽  
Tadesse Gidey Gebrezihar ◽  
Bulto Giro Boru ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Addis Ababa ◽  
Sampling Technique ◽  
Normal Structure ◽  
Bacterial Isolates ◽  
Dromedary Camels ◽  
Cross Sectional ◽  
Tissue Samples ◽  
Pathological Lesions ◽  
Isolation And Characterization

Abstract Background: Reproduction is a basic prerequisite to efficient livestock production. Reproductive performance depends upon the normal structure and function of genital organs. Methods: A cross-sectional study was conducted from November 2016 to May 2017 to identify and compare the frequency of pathological lesions in the reproductive tract and to isolate bacteria associated to uterine lesions in female dromedary camels and cows slaughtered at Akaki camel slaughter house and Addis Ababa and Adama municipal abattoirs. Abattoirs were visited once per week for 28 weeks during which three to seven animals on average were slaughtered per day. A purposive sampling technique was employed to examine reproductive tracts of all slaughtered animals (280; 140 cows and 140 camels). Following gross inspection at abattoirs, tissue samples with lesion were collected for histopathological and bacteriological investigation. Result: Various pathological lesions with different degrees of severity were observed in 48 (34.2%) and 51 (36.4%) of dromedary camels and cows, respectively. Uterine lesions were the most prevalent 21.4% lesions observed in dromedary camels followed by ovarian lesions 7.14%; while in cows, ovarian lesions were the major prevalent 16.4% lesions followed by uterine lesion 14.2%. The result showed that there were 56 bacteria isolated from cows uterine lesion with Staphylococcus species 28.5%, Streptococci species 19.6%, Coynebacterium species 8.9%, Escherichia coli 26.78%, Salmonella species 10.7% and Klebsiella species 5.35% being the prominent isolates; while in camels, there were 45 bacteria isolated with Escherichia coli 35.5%, Staphylococcus species 26.6%, Streptococcus species 13.3%, Pseudomonas species 6.6 %, Proteus species 4.4%, Salmonella species 8.8% and Klebsiella species 4.4% being the most frequently isolated. The result showed that the major isolates were similar with slightly higher in cows. Histopathologically, endometrial glands degeneration, sloughing of epithelium, peri-glandular cuffing and infiltrations of inflammatory cell were some of characteristic changes observed in uterus. Conclusions: Pathological lesions in reproductive organs in female dromedary camels and cows showed great prevalence, with similarity in bacterial isolates between the two species. The role of each reproductive lesions and bacterial isolates incriminated as causes of reproductive failures in this livestock species needs further investigation.

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