Joint X-ray crystallographic and molecular dynamics study of cellobiohydrolase I from Trichoderma harzianum: deciphering the structural features of cellobiohydrolase catalytic activity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Aiming to contribute toward the characterization of new, biotechnologically relevant cellulolytic enzymes, we report here the first crystal structure of the catalytic core domain of Cel7A (cellobiohydrolase I) from the filamentous fungus Trichoderma harzianum IOC 3844. Our structural studies and molecular dynamics simulations show that the flexibility of Tyr260, in comparison with Tyr247 from the homologous Trichoderma reesei Cel7A, is enhanced as a result of the short side-chains of adjacent Val216 and Ala384 residues and creates an additional gap at the side face of the catalytic tunnel. T. harzianum cellobiohydrolase I also has a shortened loop at the entrance of the cellulose-binding tunnel, which has been described to interact with the substrate in T. reesei Cel7A. These structural features might explain why T. harzianum Cel7A displays higher kcat and Km values, and lower product inhibition on both glucoside and lactoside substrates, compared with T. reesei Cel7A.28015669Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [2008/56255-9, 2009/54035-4, 2010/08680-2]CNPq [490022/2009-0, 471834/2009-2, 550985/2010-7, 151951/2008-0

Ecological Factors Influencing Breastfeeding Decisions among Korean Immigrant Mothers in America

There are complex relationships among individual, family, community, and social factors related to breastfeeding. Immigrant mothers, specifically, face several unique challenges to practicing breastfeeding while negotiating these factors within two cultural worlds. Grounded in the theory of planned behavior and the ecological perspective, our qualitative study findings unveil a part of the complex and dynamic process of breastfeeding decision-making among Korean immigrant mothers in the United States. To elicit mothers’ underlying beliefs of attitude and intention toward breastfeeding as immigrants, we conducted in-person interviews with 13 pregnant and postpartum Korean immigrant mothers, ages ranging from 30 to 39. The findings revealed that Korean mothers held positive attitudes toward breastfeeding. However, translation of these positive attitudes toward breastfeeding into actual practice depended on the feasibility of actual breastfeeding by mothers. To overcome several barriers to breastfeeding, such as inadequate milk supply, health concerns, employment status, and the relationship with a firstborn child, many Korean mothers combined breastfeeding with formula feeding. The factors that shaped the development of beliefs and behavioral intentions toward breastfeeding among Korean immigrant mothers included the dynamic family interactions with their children, husbands, mothers, mothers-in-law, and sisters; support from friends and infant care experts; information available through various technology and media; and Korean-specific cultural traditions. Our findings suggest possible directions for future cross-cultural research on breastfeeding within diverse family contexts, and may inform the design of population specific intervention programs

Longitudinal association of changes in diet with changes in body weight and waist circumference in subjects at high cardiovascular risk: the PREDIMED trial

Background: Consumption of certain foods is associated with long-term weight gains and abdominal fat accumulation in healthy, middle-aged and young, non-obese participants. Whether the same foods might be associated with changes in adiposity in elderly population at high cardiovascular risk is less known. Objective: Using yearly repeated measurements of both food habits and adiposity parameters, we aimed to investigate how changes in the consumption of specific foods were associated with concurrent changes in weight or waist circumference (WC) in the PREDIMED trial. Design: We followed-up 7009 participants aged 55-70 years at high cardiovascular risk for a median time of 4.8 years. A validated 137-item semi-quantitative Food Frequency Questionnaire was used for dietary assessment with yearly repeated measurements. We longitudinally assessed associations between yearly changes in food consumption (serving/d) and concurrent changes in weight (kg) or WC (cm). Results: Yearly increments in weight were observed with increased consumption (kg per each additional increase in 1 serving/d) for refined grains (0.32 kg/serving/d), red meat (0.24), potatoes (0.23), alcoholic beverages (0.18), processed meat (0.15), white bread (0.07) and sweets (0.04); whereas inverse associations were detected for increased consumption of low-fat yogurt (- 0.18), and low-fat milk (- 0.06). Annual WC gain (cm per each additional increase in 1 serving/d) occurred with increased consumption of snacks, fast-foods and pre-prepared dishes (0.28), processed meat (0.18), alcoholic beverages (0.13), and sweets (0.08); whereas increased consumption of vegetables (- 0.23), and nuts (- 0.17), were associated with reductions in WC. Conclusions: In this assessment conducted in high-risk subjects using yearly repeated measurements of food habits and adiposity, some ultra-processed foods, refined carbohydrates (including white bread), potatoes, red meats and alcohol were associated with higher weight and WC gain, whereas increases in consumption of low-fat dairy products and plant foods were associated with less gain in weight and WC. Trial registration: This study was registered at controlled-trials.com with International Standard Randomized Controlled Trial Number (ISRCTN): 35739639. Registration date: 5 October 2005.The research leading to these results was supported by the official Spanish Institutions for funding scientific biomedical research, CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN) and Instituto de Salud Carlos III (ISCIII), and through specific grants/contracts: the “FOLIUM” program within the FUTURMed project. Talent for the medicine within the future from the Fundación Instituto de Investigación Sanitaria Illes Balears (financed by 2017 annual plan of the sustainable tourism tax and at 50% with charge to the ESF Operational Program 2014–2020 of the Balearic Islands) [JK]; ERC Advanced Research Grant (340918) [MAM-G as PI]. None of the funding sources took part in the design, collection, analysis or interpretation of the data, or in the decision to submit the manuscript for publication