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Structural characterization of protein–protein interactions can provide essential details to understand biological functions at the molecular level and to facilitate their manipulation for biotechnological and biomedical purposes. Unfortunately, the 3D structure is available for only a small fraction of all possible protein–protein interactions, due to the technical limitations of high-resolution structural determination methods. In this context, low-resolution structural techniques, such as small-angle X-ray scattering (SAXS), can be combined with computational docking to provide structural models of protein–protein interactions at large scale. In this chapter, we describe the pyDockSAXS web server (https://life.bsc.es/pid/pydocksaxs), which uses pyDock docking and scoring to provide structural models that optimally satisfy the input SAXS data. This server, which is freely available to the scientific community, provides an automatic pipeline to model the structure of a protein–protein complex from SAXS data ; This work was supported by the Spanish Ministry of Science (grant BIO2016-79930-R), the European Union H2020 programme (grant MuG 676566), and the Labex EpiGenMed, an "Investissements d'avenir" program (ANR-10-LABX-12-01). The CBS is a member of France-BioImaging (FBI) and the French Infrastructure for Integrated Structural Biology (FRISBI), two national infrastructures supported by the French National Research Agency (ANR-10-INSB-04-01 and ANR-10-INSB-05, respectively). ; Peer Reviewed ; Postprint (author's final draft)

Protein content of any source is classically determined through the analysis of its nitrogen content done for more 100 years by the Kjeldahl method, and the obtained result is multiplied by a number named nitrogen conversion factor (NCF). The value of NCF is related to the amino acid composition of the protein source and to the eventual presence of side groups covalently bound to some amino acids of the protein chain. Consequently, the value of NCF cannot be identical for all sources of food proteins. The aim of this paper is to review the available knowledge on the two allowed protein sources for infant food formulas, milk and soybean, in order to bring the right scientific basis which should be used for the revision of both European legislation and Codex Standard for Infant Formulas.

1 Introduction -- 1.1 The problem -- 1.2 Overall steps in protein biosynthesis -- 2 The molecules involved in protein biosynthesis -- 2.1 Messenger RNA -- 2.2 Ribosomes -- 2.3 Transfer RNA -- 2.4 Initiator tRNA -- 2.5 Amino-acyl-tRNA synthetases -- 2.6 Elongation factors -- 2.7 Peptidyl transferase -- 2.8 Initiation factors -- 2.9 Termination factors -- References -- 3 The mechanism of protein biosynthesis and its control -- 3.1 Introduction -- 3.2 mRNA metabolism -- 3.3 Initiation complex formation -- 3.4 Elongation -- 3.5 Termination of protein biosynthesis and post-translational modification -- 3.6 RNA phage protein synthesis -- References.

Polyphenoloxidase from apple was extracted and further concentrated by cationic reversed micellar extraction. Previous to reversed micellar extraction a crude protein extract was obtained using AG2-X8 as adsorbent of phenolic compounds and the detergent Triton X-100. Forward and backward extraction conditions were optimized by using dodecyl trimethyl ammonium bromide as surfactant in the organic phase. Optimization was carried out to obtain the highest value of PPO activity recovery and the purification fold at the different experimental conditions. Under the optimum extraction conditions, PPO activity recovery was 99% and purification fold reached a value of 17, showing that reversed micellar extraction was a good technique as a first step to concentrate on a targeted enzyme. After removing some impurities by centrifuge ultrafiltration, the protein extract with PPO activity was treated by pressurized carbon dioxide and thermosonication achieving residual PPO activity values of 16 ± 3 and 9 ± 1%, respectively. Quenching experiments by iodide performed in the non-treated extract and in the treated extracts revealed conformational changes of this protein fraction reflected in the greater exposure of the fluorophore to the quencher. ; Spanish Government (MINECO) and the European Regional Development Fund (ERDF) for financial support of project CTQ2015-64396-R and AEI's contract, and to Junta de Castilla y León and ERDF for financial support of project BU301P18.

Protein-based therapeutics are highly successful in clinic and currently enjoy unprecedented recognition of their potential. More than 100 genuine and similar number of modified therapeutic proteins are approved for clinical use in the European Union and the USA with 2010 sales of US$108 bln; monoclonal antibodies (mAbs) accounted for almost half (48%) of the sales. Based on their pharmacological activity, they can be divided into five groups: (a) replacing a protein that is deficient or abnormal; (b) augmenting an existing pathway; (c) providing a novel function or activity; (d) interfering with a molecule or organism; and (e) delivering other compounds or proteins, such as a radionuclide, cytotoxic drug, or effector proteins. Therapeutic proteins can also be grouped based on their molecular types that include antibody-based drugs, Fc fusion proteins, anticoagulants, blood factors, bone morphogenetic proteins, engineered protein scaffolds, enzymes, growth factors, hormones, interferons, interleukins, and thrombolytics. They can also be classified based on their molecular mechanism of activity as (a) binding non-covalently to target, e.g., mAbs; (b) affecting covalent bonds, e.g., enzymes; and (c) exerting activity without specific interactions, e.g., serum albumin. Most protein therapeutics currently on the market are recombinant and hundreds of them are in clinical trials for therapy of cancers, immune disorders, infections, and other diseases. New engineered proteins, including bispecific mAbs and multispecific fusion proteins, mAbs conjugated with small molecule drugs, and proteins with optimized pharmacokinetics, are currently under development. However, in the last several decades, there are no conceptually new methodological developments comparable, e.g., to genetic engineering leading to the development of recombinant therapeutic proteins. It appears that a paradigm change in methodologies and understanding of mechanisms is needed to overcome major challenges, including resistance to therapy, access to ...

This study is part of the program of the interdisciplinary research group Profetas (protein foods, environment, technology and society). Profetas consists of technological, environmental and socio-economic research projects on protein food systems which result in the development of scenarios and strategies for guiding a shift towards a more plant protein based diet. The different research projects focus on the goal of identifying viable options for a more sustainable food system. Profetas arose from a concern with the increasing impact of food production and consumption on the environment and a desire to restrain human pressure on the environment.

Commercial Protein Supplements that are circulating freely nowadays are consumed not only by athletes but the wider community, especially sports activists who rely upon it to improve performance or merely for aesthetic interests. This study aims to analyze the nutritional content of the five supplements circulating freely in Indonesia to then compare it with the claims on the packaging label. We analyzed five samples of popular supplements in Indonesia obtained online and then tested in three copies for each sample. The actual total protein in the supplement sample is measured using the Kjeldahl method where the appropriate nitrogen material is converted to percentage of protein by multiplying a factor of 6.38 in duplicate. Then the research data processed and analyzed using Microsoft Excel 2016 computer programs then by Statistical Program for Social Sciences (SPSS), consecutively. Relationships between different tests were evaluated by calculating the relevant correlation coefficients (Pearson linear correlation) (p <0.05). Analysis of variance (ANOVA) was used to compare the differences between products with different manufacturing processes (p <0.05). Based on the analysis results, only two of the five samples studied has a minimum of 80% compatibility with the claim on the packaging label. Several main factors including inaccurate analysis, preparation processing on products that triggers protein denaturation, inadequate storage, and regulations that have just been set so that producers are still free to write Nutrition Value Information with a fairly low level of accuracy. This research is expected to be able to help the evaluation for producers and the government (BPOM) to be able to provide correct information to consumers so that maximum physiological benefits can be obtained. ; Commercial Protein Supplements that are circulating freely nowadays are consumed not only by athletes but the wider community, especially sports activists who rely upon it to improve performance or merely for aesthetic interests. This study aims to analyze the nutritional content of the five supplements circulating freely in Indonesia to then compare it with the claims on the packaging label. We analyzed five samples of popular supplements in Indonesia obtained online and then tested in three copies for each sample. The actual total protein in the supplement sample is measured using the Kjeldahl method where the appropriate nitrogen material is converted to percentage of protein by multiplying a factor of 6.38 in duplicate. Then the research data processed and analyzed using Microsoft Excel 2016 computer programs then by Statistical Program for Social Sciences (SPSS), consecutively. Relationships between different tests were evaluated by calculating the relevant correlation coefficients (Pearson linear correlation) (p <0.05). Analysis of variance (ANOVA) was used to compare the differences between products with different manufacturing processes (p <0.05). Based on the analysis results, only two of the five samples studied has a minimum of 80% compatibility with the claim on the packaging label. Several main factors including inaccurate analysis, preparation processing on products that triggers protein denaturation, inadequate storage, and regulations that have just been set so that producers are still free to write Nutrition Value Information with a fairly low level of accuracy. This research is expected to be able to help the evaluation for producers and the government (BPOM) to be able to provide correct information to consumers so that maximum physiological benefits can be obtained.