scholarly journals Engineered Stable 5-Hydroxymethylfurfural Oxidase (HMFO) from 8BxHMFO Variant of Methylovorus sp. MP688 through B-Factor Analysis

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1503
Author(s):  
Qiuyang Wu ◽  
Dong Lu ◽  
Shuming Jin ◽  
Jie Lu ◽  
Fang Wang ◽  
...  

What is known as Furan-2,5-dicarboxylic acid (FDCA) is an attractive compound since it has similar properties to terephthalic acid. Further, 5-hydroxymethylfurfural oxidase (HMFO) is an enzyme, which could convert HMF to FDCA directly. Most wild types of HMFO have low activity on the oxidation of HMF to FDCA. The variant of 8BxHFMO from Methylovorus sp. MP688 was the only reported enzyme that was able to perform FDCA production. However, the stabilization of 8BxHMFO is still not that satisfactory, and further improvement is necessary for the industrial application of the enzyme. In this work, stability-enhanced HMFO from 8BxHFMO was engineered through employing B-factor analysis. The mutation libraries were created based on the NNK degeneracy of residues with the top ten highest B-factor value, and two of the effective mutants were screened out through the high throughput selection with the horseradish peroxidase (HRP)-Tyr assay. The mutants Q319K and N44G show a significantly increased yield of FDCA in the reaction temperature range of 30 to 40 °C. The mutant Q319K shows the best performance at 35 °C with a FDCA yield of 98% (the original 8BxHMFO was only 85%), and a half-life exceeding 72 h. Moreover, molecular dynamic simulation indicates that more hydrogen bonds are formed in the mutants, which improves the stability of the protein structure. The method could enhance the design of more stable biocatalysts; and provides potential for the further optimization and utilization of HMFO in biotechnological processes.

1967 ◽  
Vol 15 (7) ◽  
pp. 375-380 ◽  
Author(s):  
WERNER STRAUS

Small phagosomes (micropinocytic vesicles and vacuoles) which had taken up injected horseradish peroxidase were identified by staining for peroxidase with benzidine and H2O2. Because of the small size of the granules and the possibility of artifacts, previously described procedures had to be modified in several respects. Prefixation of the tissue by perfusion at 37°C prevented artifacts of diffusion and adsorption of peroxidase. The blue product of the reaction of peroxidase with benzidine in the small phagosomes was preserved and fading to brown was prevented by cooling the tissue section to –10° to –15°C during its processing through polar media. The blue reaction product was stable as soon as the section was transferred to an apolar medium. Small phagosomes were visualized together with lysosomes and phago-lysosomes in the same cells by double staining for acid phosphatase and peroxidase in contrasting colors. The incubation for acid phosphatase was performed at 4°C since low temperature increased the stability of peroxidase in the acid medium. Factors which form the basis for other improvements of the procedure are discussed.


1980 ◽  
Vol 47 (3_suppl) ◽  
pp. 1160-1162 ◽  
Author(s):  
Stephen L. Franzoi ◽  
Benjamin J. Reddish

The factor structure of Rosenberg's Stability of Self Scale (1965) was investigated via principal components factor analysis. Data from 92 male and 171 female undergraduates yielded a one-factor solution, supporting Rosenberg's contention that the scale is unidimensional.


2017 ◽  
Vol 32 (2) ◽  
Author(s):  
Shannon Gwin ◽  
Paul Branscum ◽  
E. Laurette Taylor

The purpose of this study was to create a valid and reliable instrument to evaluate theory-basedbeliefs towards physical activity among clergy members. Data were collected from 174 clergy that par-ticipated in a 15-item online and paper-based survey. Psychometric properties of the instrument includedconfirmatory factor analysis (construct validity), and cronbach’s alpha (internal consistency reliability).In addition, the stability (test-retest reliability) of each subscale was evaluated with a sub-sample of 30participants. Results show the instrument was both valid and reliable, and will be useful in future studiestargeting this population. Future implications are discussed.


2017 ◽  
Vol 8 (11) ◽  
pp. 7324-7329 ◽  
Author(s):  
Tyler M. Porter ◽  
Gavin P. Heim ◽  
Clifford P. Kubiak

The measurement of the dimerization constants of hydrogen-bonded ruthenium complexes (12, 22, 32) linked by a self-complementary pair of 4-pyridylcarboxylic acid ligands in different redox states is reported.


2012 ◽  
Vol 68 (6) ◽  
pp. o1711-o1711 ◽  
Author(s):  
Vandavasi Koteswara Rao ◽  
Matthias Zeller ◽  
Sherri R. Lovelace-Cameron

The asymmetric unit of the title compound, C10H8N2·C8H6O4, consists of one half-molecule of each moiety, 4,4′-bipyridine (bpy) and terephthalic acid (bdc), both being located on crystallographic inversion centers. They are linked together via strong intermolecular O—H...N hydrogen bonds, forming infinite chains propagating along [1-21]. The chains are further connected through C—H...O interactions giving sheets in (012). The sheets are linked via π–π interactions between the bpy rings and the bdc–bpy rings [centroid–centroid distances = 3.690 (2) and 3.869 (2) Å], resulting in the formation of a three-dimensional supramolecular layer-like structure.


Author(s):  
Hepi Wahyuningsih ◽  
Dyna Rahayu Suci Pertiwi

This study aims to adapt the Sanctification of Marriage Questionnaire for Muslims inIndonesia. Adaptation of the Sanctification of Marriage Questionnaire is carried out throughthe stages: translation, providing evidence of construct validity and reliability. Evidence of construct validity was carried out by exploratory factor analysis followed by MGCFA (Multi-Group Confirmatory factor Analysis). In this study, we used a composite reliability. Subjects to reveal the factor structure of sanctification of marriage were 160 married individuals, while the subjects to test the stability of factor structure consisted of 102 husbands and 111 wives. The result of exploratory factor analysis shows that the construct of sanctification of marriage has three factors / dimensions, namely: belief, perceived sacred qualities and manifestation of God. The structure stability of sanctification of marriage was then empirically tested by MGCFA. The results of MGCFA showed that the three factors / dimensions of sanctification of marriage proved stable. The composite reliability coefficient of the Sanctification of Marriage Questionnaire was in a good category. Further research can be carried out to provide evidence of construct validity with predictive validity and concurrent validity of the Sanctification of Marriage Questionnaire. Limitations in this study are discussed further.Keywords: exploratory factor analysis, multi-group confirmatory factor analysis, muslim,sanctification of marriage, scale adaptation


2017 ◽  
Vol 5 (4) ◽  
pp. 44
Author(s):  
Rüştü Yeşil

use after also being checked by linguists. The validity analysis of the scale for the data collected was performed with exploratory factor analysis and item-total correlation tests, while the property of reliability was determined using the Cronbach’s alpha internal consistency coefficient and the stability test was carried out by determining the relationship between two applications conducted at an interval of the five weeks. The scale, which is called the “Scale for Determining the Civic-Mindedness Levels of Individuals” is a five-step Likert-type scale and consists of 27 items that can be collected under three factors. The factor names are “Openness to Criticism/Development”, “Participation/Activeness” and “Lack of Prejudice/Flexibility”. The KMO value of the scale was 0.956; and the Bartlett Test values were x2=11001.719; sd=351; p<0.000. Items in the scale accounted for 56.619% of the total variance. As a result of the confirmatory factor analysis, the χ2 value was 808.07 and the degree of freedom was 321. Χ2/df is 2.51. The fit indices of the scale were determined as RMSEA=0.067; S-RMR=0.049; NFI=0.97. The item-total corrected correlation coefficients of the items in the scale varied between 0.40 and 0.703 (p<.01). The reliability coefficient of the scale was Cronbach’s alpha at 0.954 and the stability coefficients of the items were between 0.496 and 0.674 (p<,01).


Sign in / Sign up

Export Citation Format

Share Document