209 research outputs found

    Do Electrostatic Interactions with Positively Charged Active Site Groups Tighten the Transition State for Enzymatic Phosphoryl Transfer?

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    The effect of electrostatic interactions on the transition-state character for enzymatic phosphoryl transfer has been a subject of much debate. In this work, we investigate the transition state for alkaline phosphatase (AP) using linear free-energy relationships (LFERs). We determined kcat/KM for a series of aryl sulfate ester monoanions to obtain the Br├Şnsted coefficient, ╬▓lg, and compared the value to that obtained previously for a series of aryl phosphorothioate ester dianion substrates. Despite the difference in substrate charge, the observed Br├Şnsted coefficients for AP-catalyzed aryl sulfate and aryl phosphorothioate hydrolysis (Ôłĺ0.76 ┬▒ 0.14 and Ôłĺ0.77 ┬▒ 0.10, respectively) are strikingly similar, with steric effects being responsible for the uncertainties in these values. Aryl sulfates and aryl phosphates react via similar loose transition states in solution. These observations suggest an apparent equivalency of the transition states for phosphorothioate and sulfate hydrolysis reactions at the AP active site and, thus, negligible effects of active site electrostatic interactions on charge distribution in the transition state


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    Pollen viability of eight quince cultivars (╩╗Leskovacka╩╝, ╩╗Vranjska╩╝, ╩╗Morava╩╝, ╩╗Pazardzijska╩╝, ╩╗Hemus╩╝, ╩╗Asenica╩╝, ╩╗Portugal╩╝ and ╩╗Triumph╩╝), was studied in the two-year period (2011-2012). Testing of pollen viability was performed using two methods: the staining of pollen with acetocarmine (indirect method) and pollen germination in vitro with sucrose and agar-agar (direct method). Studied cultivars differed significantly in terms of pollen viability. The lowest percentage of stained pollen grains was detected in ╩╗Leskovacka╩╝ cultivar (70.29%) and the highest in the cultivars ╩╗Asenica╩╝, ╩╗Hemus╩╝ and ╩╗Triumph╩╝ (over 90%). Similarly to that, the lowest percentage of pollen germination was obtained in ╩╗Leskovacka╩╝ cultivar (62.86%) and the highest in the cultivars ╩╗Morava╩╝, ╩╗Asenica╩╝, and ╩╗Triumph╩╝ (over 80%). With the exception of ╩╗Portugal╩╝ cultivar, the values of pollen viability determined by staining with acetocarmine were higher for 3-15% compared to the pollen germination in vitro. However, values obtained using these tho methods are highly positively correlated. On the basis of obtained results, the both methods can be recommended as reliable tests for pollen viability of quince, although priority should be given to the method of pollen germination in vitro, because it is more accurate. All tested cultivars are distinguished for high pollen viability, and can be successfully used as male parents in hybridization. In addition, they also can be recommended as a good pollenisers when are planting new quince orchards

    Uncovering the Role of p38 Family Members in Adipose Tissue Physiology.

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    The complex functions of adipose tissue have been a focus of research interest over the past twenty years. Adipose tissue is not only the main energy storage depot, but also one of the largest endocrine organs in the body and carries out crucial metabolic functions. Moreover, brown and beige adipose depots are major sites of energy expenditure through the activation of adaptive, non-shivering thermogenesis. In recent years, numerous signaling molecules and pathways have emerged as critical regulators of adipose tissue, in both homeostasis and obesity-related disease. Among the best characterized are members of the p38 kinase family. The activity of these kinases has emerged as a key contributor to the biology of the white and brown adipose tissues, and their modulation could provide new therapeutic approaches against obesity. Here, we give an overview of the roles of the distinct p38 family members in adipose tissue, focusing on their actions in adipogenesis, thermogenic activity, and secretory function.ML was supported by a Spanish grant MINECO-FEDERSAF2015- 74112-JIN and Fundación AECC: INVES20026LEIV. MP was a fellow of the Spanish State programme for the Promotion of Talent and its Employment (PRE2018-083631). IN was funded by the EFSD/Lilly grants (2017 and 2019), the CNIC IPP FP7 Marie Curie Programme (PCOFUND-2012-600396), an EFSD Rising Star award (2019), and the JDC-2018-Incorporación (MIN/JDC1802). GS received funding from the following programs and organizations: European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement n° ERC 260464, the EFSD/Lilly European Diabetes Research Programme, the BBVA Foundation Leonardo Grants program for Researchers and Cultural Creators (Investigadores-BBVA-2017) IN[17]_BBM_BAS_0066, MINECO-FEDER SAF2016-79126-R, and the Comunidad de Madrid (IMMUNOTHERCAN-CM S2010/BMD-2326 and B2017/BMD-3733). The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia, Innovación y Universidades (MCNU), and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

    Reducing the Sodium Chloride Content in Chicken Pate by Using Potassium and Ammonium Chloride

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    AbstractThe aim of this research was to investigate possibility of chicken pate production with reduced sodium chloride content, as well as to establish changes in sensory characteristics. In the study, six experimental groups of chicken pate were produced with the same basic ingredients, but different amounts of added salts. Sensory evaluation was performed in order to determine general taste acceptability, and of the sodium and potassium levels in the chicken pate. The pate from EI and EII groups in which the amount of added sodium chloride was reduced and/or partially substituted with ammonium chloride had a most acceptable taste


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    Background: In order to explore whether gender differences are present in self-reports on personality measures when all Major Depressive Disorder (MDD) participants are diagnosed at an equal intensity, the aim of this study was to investigate individual and gender differences in personality between healthy participants and those suffering from severe feature MDD. Subjects and methods: The sample consisted of 632 participants: 385 in the healthy control group and 247 MDD, the latter comprised of patients in their first diagnosed episode or recurrent. The Hamilton Depression Rating Scale (HAM-D) was used to measure symptom severity. BeckÔÇÖs Depression Inventory was administered when depression symptoms had lessened, establishing it as minor when filling out the personality questionnaire (NEO-PI-R). Results: The results indicate a broad difference in personality between the healthy control and the MDD groups. High neuroticism and low extraversion, accompanied by low scores on openness and conscientiousness, were the most important personality dimensions in understanding distinctions. While agreeableness did not indicate any important role, it did significantly influence the understanding of gender differences within groups. Females were found more agreeable in both groups, but those from the healthy group were also more open and conscientiousness than healthy males. Females from the MDD group were found to be also higher on neuroticism than males of the same group. Conclusions: A general conclusion from the study is that personality dimensions are more important in understanding vulnerability to depression in comparison to gender differences in personality within groups. As females in the MDD group tend to self-report higher levels of agreeableness and neuroticism than do males in the same group when the level of their depression is categorized as equal MDD-severe type, this may influence practitioners to unequally diagnose depression in males and females
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