scholarly journals Conformational change in individual enzyme molecules

2015 ◽  
Vol 93 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Jeremie J. Crawford ◽  
Frannie Itzkow ◽  
Joanna MacLean ◽  
Douglas B. Craig
Keyword(s):  
Heat Shock ◽  
Electrophoretic Mobility ◽  
Conformational Changes ◽  
Average Rate ◽  
Electrophoretic Mobilities ◽  
Significant Difference ◽  
Average Change ◽  
Before And After ◽  
Enzyme Molecules ◽  
Individual Enzyme

Single β-galactosidase molecule assays were performed using a capillary electrophoresis based protocol, employing post-column laser-induced fluorescence detection. In a first set of experiments, the distribution of single β-galactosidase molecule catalytic rates and electrophoretic mobilities were determined from lysates of Escherichia coli strains containing deletions for different heat shock proteins and grown under normal and heat shock conditions. There was no clear observed pattern of effect of heat shock protein expression on these distributions. In a second set of experiments, individual enzyme molecule catalytic rates were determined at 21 °C before and after 2 sequential brief periods of incubation at 50, 28, and 10 °C. The brief incubations at 50 °C caused a change in the enzyme molecules resulting in a different catalytic rate. Any given molecule was just as likely to show an increase in rate as a decrease, resulting in no significant difference in the average rate of the population. The average change in individual molecule rate was dependent upon the temperature of the brief incubation period, with a lesser average change occurring at 28 °C and negligible change at 10 °C. A third set of experiments was similar to that of the second with the exception that it was electrophoretic mobility that was considered. This provided a similar result. Incubation at higher temperature resulted in a change in electrophoretic mobility. The probability of an individual molecules switching to a higher mobility was approximately equal to that of switching to a lower mobility, resulting in no net average change in the population. The magnitude of the changes in electrophoretic mobilities suggest that the associated conformational changes are subtle.

The Effecet Of Aspirin On The Activity Of Platelet Density Subpopulations As Measured By Electrophoretic Mobility

1981 ◽  
Author(s):  
R J LeBeau ◽  
J A Menna ◽  
R C Guntuer
Keyword(s):  
Electrophoretic Mobility ◽  
Electrophoretic Mobilities ◽  
Significant Difference ◽  
Male Subjects ◽  
Heavy Group ◽  
Light Medium

Whole populations of platelets were harvested from male subjects by centrifugation at 60g. Density subpopulations in the ranges: 1.040≤p1≤1.058, 1.058 ≤p2≤1.068, and 1.068 ≤p3≤1.080 were obtained using the Stractan method of Corash. These correspond approximately to the “light,” “medium,” and “heavy” subpopulations of Karpatkin. Electrophoretic mobilities (EB) of normal platelets and those following the subjects’ ingestion of aspirin where measured using a Zeiss Cytophero- meter. It is shown that there is a highly significant difference in EB between the three subpopulations of normal platelets and that the EB of the heavy group is significantly more affected by aspirin than that of the medium and light groups.

scholarly journals Spiritual Emotional Freedom Technique (SEFT) terhadap Kualitas Hidup Pasien HIV/AIDS

2020 ◽  
Vol 4 (1) ◽  
pp. 178-186
Author(s):  
Defia Roza ◽  
Sila Dewi Anggreni ◽  
Heppi Sasmita ◽  
Yessi Fadriyanti ◽  
Nova Yanti
Keyword(s):  
Quality Of Life ◽  
Average Rate ◽  
P Value ◽  
Hiv Patients ◽  
Keywords Hiv ◽  
Significant Difference ◽  
Before And After ◽  
Quasi Experimental ◽  
Hiv Aids

This study aimed to determine the effectiveness of SEFT interventions in improving the quality of life of HIV / AIDS patients in Padang City. The design of this study was a Quasi-experimental design with one group pretest and posttest. This study found that the average quality of life of HIV patients before SEFT administration was 97.07, and the average rate of life of HIV patients after SEFT administration was 102.6. It can be seen that the mean difference between before and after SEFT action is 5.57 with a standard deviation of 6.98. The statistical test results obtained p-value = 0.011. In conclusion, there is a significant difference between the quality of life of HIV patients before and after SEFT treatment.   Keywords: HIV, Quality of Life, SEFT

The Heatshockprotein-90 Inhibitor IPI-504 Potently Overcomes Tyrosinekinase Inhibitor-Induced Activation of Cell Protection Mechanisms and Degrades HSP-Client Proteins KIT and FLT3 In Acute Leukemia Models

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3982-3982
Author(s):  
Marcus Schittenhelm ◽  
Tanja Grandl ◽  
Emmanuel Normant ◽  
Helmut R. Salih ◽  
Kerstin M Kampa-Schittenhelm
Keyword(s):  
Heat Shock ◽  
Acute Leukemia ◽  
Hsp90 Inhibitor ◽  
Acute Leukemias ◽  
Significant Difference ◽  
Before And After ◽  
Protection Mechanisms ◽  
Tk Inhibitors ◽  
Client Proteins ◽  
Tki Treatment

Abstract Abstract 3982 Activating mutations of FLT3 and KIT class III receptor tyrosine kinases (TK) are associated with acute leukemias and systemic mastocytosis. Despite the encouraging therapeutic potential of TK inhibitors (TKI), monotherapy often is not sufficient to obtain lasting responses. Here we show that TKI therapy may lead to cellular protection mechanisms including stabilization/repair of DNA, as well as protection of the function of heat shock proteins. We further demonstrate that degradation of heat shock protein 90 (HSP90) client proteins, FLT3 and KIT, by the HSP90 inhibitor IPI-504, leads to antitumor effects in acute leukemia and mastocytosis models; including additive to synergistic antiproliferative and proapoptotic activity after TKI treatment. To explore the immediate downstream signaling effects of mutant FLT3 and KIT inhibition in acute leukemia and mastocytosis models, we performed unbiased phoshoproteomic analyses of cells before and after TKI treatment. Phosphopeptides that displayed a significant difference in phosphorylation before and after FLT3/KIT inhibition with Imatinib or Sunitinib at IC90 were immunoaffinity purified, and identified by tandem mass spectrometry. Degradation of FLT3 and KIT after HSP90 inhibition was studied by immunoblotting. Antiproliferative and proapoptotic effects of the HSP90 inhibitor IPI-504 alone, or in combination with TKI treatment, were studied in different leukemia and mastocytosis cell models, and in an isogenic BaF/3 model harboring different clinically relevant KIT and FLT3 mutations. Phoshoproteomics revealed a significant upregulation in phosphorylation of DNA and protein function stabilizing proteins, including HSP members in mutant KIT and FLT3 cell lines. Both FLT3 and KIT turned out to be client proteins of HSP90, and IPI-504 was able to degrade FLT3 and KIT protein, resulting in a strong potentiation of the antiproliferative and proapoptotic effects achieved by TK inhibitors alone. Of interest, IPI-504 displayed antitumor activity even as monotherapy in some leukemia and mastocytosis cell line models. Our data suggest that TK inhibition of FLT3 or KIT causes initiation of cell protective mechanisms, including activation of HSPs, which can therapeutically be targeted by HSP90 inhibitors such as IPI-504. These results provide a rationale to combine TKI with HSP inhibitors to optimize TKI therapy in patients with hematopoietic malignancies. Disclosures: Normant: Infinity pharmaceuticals: Employment.

Analyzing reactions of single mechanoenzyme molecules by light microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 426-427
Author(s):  
Jeff Gelles
Keyword(s):  
Image Processing ◽  
Reaction Mechanisms ◽  
Transient State ◽  
Nanometer Scale ◽  
Reaction Intermediates ◽  
Enzyme Molecule ◽  
Directed Movement ◽  
Enzyme Molecules ◽  
Individual Enzyme ◽  
Single Reaction

Mechanoenzymes are enzymes which use a chemical reaction to power directed movement along biological polymer. Such enzymes include the cytoskeletal motors (e.g., myosins, dyneins, and kinesins) as well as nucleic acid polymerases and helicases. A single catalytic turnover of a mechanoenzyme moves the enzyme molecule along the polymer a distance on the order of 10−9 m We have developed light microscope and digital image processing methods to detect and measure nanometer-scale motions driven by single mechanoenzyme molecules. These techniques enable one to monitor the occurrence of single reaction steps and to measure the lifetimes of reaction intermediates in individual enzyme molecules. This information can be used to elucidate reaction mechanisms and determine microscopic rate constants. Such an approach circumvents difficulties encountered in the use of traditional transient-state kinetics techniques to examine mechanoenzyme reaction mechanisms.

Factor VIII-Related Activities in Normal, Haemophilic and von Willebrand’s Disease Platelet Fractions

1978 ◽  
Vol 40 (02) ◽  
pp. 288-301 ◽  
Author(s):  
P Meucci ◽  
I R Peake ◽  
A L Bloom
Keyword(s):  
Factor Viii ◽  
Electrophoretic Mobility ◽  
Concanavalin A ◽  
Freezing And Thawing ◽  
Von Willebrand's Disease ◽  
Factor Viii Related Antigen ◽  
Von Willebrand’S Disease ◽  
Normal Plasma ◽  
Significant Difference ◽  
Ristocetin Cofactor

SummaryFactor VIII-related activities have been studied in platelet fractions in order to try to reconcile the conflicting findings of other workers, and to extend the studies. In platelets from 16 normal subjects procoagulant factor VIII was not detected. The amount of factor VIII-related antigen (FVIIIR: AG) in the cytosol per mg of protein was about twice that in the membrane fraction and about ten times that in the debris fraction. There was no significant difference between the amount of FVIIIR: AG and ristocetin cofactor (RistCof) activity in each fraction. The findings in haemophilic platelets were similar. In von Willebrand’s disease (vWd) one serverely affected patient had no detectable factor VIII related activities in any platelet fraction. In 5 patients with intermediate vWd results were normal. In a further 5, with more prolonged bleeding times, no FVIIIR: RistCof was detected in platelets, despite a normal amount of FVIIIR: AG in the cytosol and debris. The electrophoretic mobility of cytosol FVIIIR: AG was increased in all normals and patients, while that in the membrane and debris fractions had normal mobility. Cytosol FVIIIR: AG eluted later than normal FVIIIR: AG on gel filtration on Sepharose 2B, and also showed reduced antibody binding in an immunoradiometric assay. Precipitation of FVIIIR: AG by concanavalin A was incomplete in all platelet fractions from normals, and even more reduced in vWd platelet fractions. The results suggest the possibility of two types of platelet FVIIIR: AG.A factor VIII-related antigen was shown to be associated with normal washed platelets by immunofluorescence techniques (Bloom et al. 1973). Since then, several studies have been reported on the localisation of factor VIII related antigen (FVIIIR: AG), factor VIII procoagulant activity (FVIII: C) and factor VIII related ristocetin cofactor activity (FVIIIR: RistCof) within the platelets. Initially, Howard et al. (1974) indicated that FVIIIR: AG was firmly bound to the platelet membrane, and noted that in lysed platelets the level of FVIIIR: AG as measured by electroimmunodiffusion was higher than that in whole platelet suspensions. However, further studies by Nachman and Jaffe (1975) showed that FVIIIR: AG was also present to a considerable extent in the granules, and they detected none in the platelet cytosol. Bouma and colleagues (1975) were, however, able to find FVIIIR: AG and FVIIIR: RistCof in the cytosol upon freezing and thawing platelets. This FVIIIR: AG had an electrophoretic mobility comparable to that of normal plasma. They also noted that platelets which were air dried apparently had a granular FVIIIR:AG localisation by immunfluorescence; however, intact platelets in suspension did not stain by this method.Recently Ruggeri et al. (1977) and Sultan et al. (1977) have also found FVIIIR: AG in the cytosol, and the former authors reported it to have increased electrophoretic mobility when compared to normal plasma FVIIIR:AG. Results concerning the localisation of FVIIIR: AG in normal platelets have thus been conflicting. Similarly, in the few reports available concerning platelet FVIIIR: AG in von Willibrand’s disease variable results have also been obtained (Ruggeri et al. 1977, Howard et al. 1974, Shearn et al. 1974 and Bouma et al. 1975).In this study we report on the localisation of factor VIII-related activities in normal, haemophilic and von Willebrand’s disease platelets using available standard techniques as well as precipitation of FVIIIR: AG with the plant lectin concanavalin A, a procedure which has been shown to detect abnormal forms of FVIIIR:AG in certain types of von Willebrand’s disease (Peake and Bloom 1977).

The influence of osteopathic correction on the rate of various rhythms of the body

2019 ◽  
pp. 64-71 ◽  
Author(s):  
A. E. Chernikova ◽  
Yu. P. Potekhina
Keyword(s):  
Heart Rate ◽  
Respiratory Rate ◽  
Age Groups ◽  
Biomechanical Properties ◽  
Dispersion Analysis ◽  
The Body ◽  
Body Tissues ◽  
Age Related ◽  
Significant Difference ◽  
Before And After

Introduction. An osteopathic examination determines the rate, the amplitude and the strength of the main rhythms (cardiac, respiratory and cranial). However, there are relatively few studies in the available literature dedicated to the influence of osteopathic correction (OC) on the characteristics of these rhythms.Goal of research — to study the influence of OC on the rate characteristics of various rhythms of the human body.Materials and methods. 88 adult osteopathic patients aged from 18 to 81 years were examined, among them 30 men and 58 women. All patients received general osteopathic examination. The rate of the cranial rhythm (RCR), respiratory rate (RR) heart rate (HR), the mobility of the nervous processes (MNP) and the connective tissue mobility (CTM) were assessed before and after the OC session.Results. Since age varied greatly in the examined group, a correlation analysis of age-related changes of the assessed rhythms was carried out. Only the CTM correlated with age (r=–0,28; p<0,05) in a statistically significant way. The rank dispersion analysis of Kruskal–Wallis also showed statistically significant difference in this indicator in different age groups (p=0,043). With the increase of years, the CTM decreases gradually. After the OC, the CTM, increased in a statistically significant way (p<0,0001). The RCR varied from 5 to 12 cycles/min in the examined group, which corresponded to the norm. After the OC, the RCR has increased in a statistically significant way (p<0,0001), the MNP has also increased (p<0,0001). The initial heart rate in the subjects varied from 56 to 94 beats/min, and in 15 % it exceeded the norm. After the OC the heart rate corresponded to the norm in all patients. The heart rate and the respiratory rate significantly decreased after the OC (р<0,0001).Conclusion. The described biorhythm changes after the OC session may be indicative of the improvement of the nervous regulation, of the normalization of the autonomic balance, of the improvement of the biomechanical properties of body tissues and of the increase of their mobility. The assessed parameters can be measured quickly without any additional equipment and can be used in order to study the results of the OC.

Protein Flexibility Catalyzes a Cell Signaling Reaction of the Ras-GAP Complex

2019 ◽  
Author(s):  
Keiei Kumon ◽  
Masahiro Higashi ◽  
Shinji Saito ◽  
Shigehiko Hayashi
Keyword(s):  
Cell Signaling ◽  
Conformational Changes ◽  
Catalytic Reaction ◽  
Protein Complex ◽  
Enzyme Mechanism ◽  
Activation Free Energy ◽  
Chemical Catalysis ◽  
Simple Chemical ◽  
A Cell ◽  
Enzyme Molecules

Many enzyme molecules exhibit characteristic global and slow dynamics which furnish them with allostery realizing remarkable molecular functionalities more than simple chemical catalysis. However, molecular mechanism of a catalytic reaction associated with the molecular flexibility of enzymes is not well-understood. Here we report a hybrid molecular simulation study on GTPase activity of a Ras-GAP protein complex for cell signaling termination. We unveiled that extensive conformational changes of the protein complex and exclusion of internal water molecules are induced upon the transition state (TS) formation in the catalytic reaction and significantly lower the reaction activation free energy. We also revealed that tumor-related mutations perturb those conformational changes upon the TS formation, leading to reduction of the catalytic activity. The findings of the remarkably dynamic protein conformation directly linking to the catalytic reaction have broad implications for understanding of enzyme mechanism and for developments of allosteric drugs and novel catalysts.

Melatih Kepemimpinan Perangkat Desa Kebonharjo Kulonprogo: Membangun Sikap Anti Korupsi

2018 ◽  
Vol 1 ◽  
pp. 107
Author(s):  
Adi Heryadi ◽  
Evianawati Evianawati
Keyword(s):  
Transformational Leadership ◽  
Data Collection ◽  
Paired Samples ◽  
Significant Difference ◽  
Before And After ◽  
Post Test ◽  
Sample Test ◽  
Corruption Perception ◽  
Measuring Tool

This study aims to prove whether transformational leadership training is effective for building anti-corruption attitudes of villages in Kebonharjo village, subdistrict Samigaluh Kulonprogo. This research is an experimental research with one group pre and posttest design.Subject design is 17 people from village of 21 candidates registered. Measuring tool used in this research is the scale of anti-corruption perception made by the researcher referring to the 9 anti-corruption values with the value of reliability coefficient of 0.871. The module used as an intervention made by the researcher refers to the transformational leadership dimension (Bass, 1990). The data collected is analyzed by statistical analysis of different test Paired Sample Test. Initial data collection results obtained sign value of 0.770 which means> 0.05 or no significant difference between anti-corruption perception score between before and after training. After a period of less than 1 (one) month then conducted again the measurement of follow-up of the study subjects in the measurement again using the scale of anti-corruption perception. The results of the second data collection were analysed with Paired Samples Test and obtained the value of 0.623 sign meaning p> 0.05 or no significant difference between post test data with follow-up data so that the hypothesis of this study was rejected.

SUBLINGUAL VITAMIN D3 DRUG THERAPY IN VITAMIN D DEFICIENCY PATIENTS AT PRAVARA RURAL HOSPITAL

2019 ◽  
pp. 18-20
Author(s):  
Sanjeeva Kumar Goud T ◽  
Rahul Kunkulol
Keyword(s):  
Vitamin D ◽  
Vitamin D Deficiency ◽  
Vitamin D3 ◽  
Serum Vitamin ◽  
Cross Sectional ◽  
Serum Vitamin D ◽  
Significant Difference ◽  
Before And After

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route

STUDY CLINICAL FEATURE AND RESULT OF TREATMENT PHACOMORPHIC GLAUCOMA

2015 ◽  
pp. 71-75
Author(s):  
Van Nam Phan ◽  
Ba Ken Tran
Keyword(s):  
Visual Acuity ◽  
Intraocular Pressure ◽  
Statistical Significance ◽  
Corneal Edema ◽  
Clinical Feature ◽  
Anterior Chamber Angle ◽  
Male Population ◽  
Significant Difference ◽  
Operative Complications ◽  
Before And After

Purpose: Study clinical feature of phacomorphic glaucoma. To evaluate the result of treatment phacomorphic glaucoma. Method: The retrospective, interventional study on 36 cases with phacomorphic glaucoma who underwent treated at Hue Central Hospital from 6/2010 to 6/2011. Standard of research: visual, IOP, before and after surgery, accompanying lesions and post-operative complications. The surgery is considered successful when postoperative IOP less than 21 mmHg. Results: Age 50-59 presented 30.5 percent, ≥ 60 presented 91.7 percent. There was a slight female preponderance (66.7%) compared to the male population (33.3%) which implies a statistically marginally significant difference. However there was no statistical significance difference when compared by the two subgroups. Patient in country presented 61,1% and city presented 38,9%. The duration between the onset of pain and surgery from 0 to < 5 days (77.8%), from 6 to 10 (16.7%) and >10 days presented 5.5%. The preoperative intraocular pressure 35 to 45mmHg (47.2%), 46-55 (30.6%), 56-65 (13.9%) and more than 65 presented 8.3%. The visual acuity preoperation less than 1metre count finger (94.5%), less than 3 metre count finger presented 5.5%. Close anterior chamber angle presented 80.6% and shallow was presented 19.4%. Corneal edema presented 100%, iritis presented 94.4%, dilated pupil larger 5mm presented 83.3%, Synchynea iris and cataract presented 72.2%. ECCE, implantation IOL combined trabeculectomy presented 11.1%, Phaco, implantation IOL combined trabeculectomy presented 69,5%, ECCE implantation IOL presented 5.6%, Phaco, implantation IOL presented 13.8%. Postoperative visual acuity from 1/10 to 5/10 presented 72.2%, no case have VA larger than 5/10. Postoperative 3 months VA 1/10 to 5/10 presented 72.2%, larger VA 5/10 presented 8.3%. Postoperative 3 months intraocular pressure ≤ 21mmHg presented 91.7%, 22 to 24mmHg presented 8.3%, no case have IOP ≥25mmHg. Postoperative edema presented 58.3%, iritis presented 58.3%. Key words: phacomorphic Glaucoma

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