共查询到20条相似文献,搜索用时 15 毫秒
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M.Sc. Katharina Heller M.Sc. Philipp Ochtrop M.Sc. Michael F. Albers Florian B. Zauner Prof. Dr. Aymelt Itzen Prof. Dr. Christian Hedberg 《Angewandte Chemie (International ed. in English)》2015,54(35):10327-10330
We present a new protein labeling method based on the covalent enzymatic phosphocholination of a specific octapeptide amino acid sequence in intact proteins. The bacterial enzyme AnkX from Legionella pneumophila has been established to transfer functional phosphocholine moieties from synthetically produced CDP‐choline derivatives to N‐termini, C‐termini, and internal loop regions in proteins of interest. Furthermore, the covalent modification can be hydrolytically removed by the action of the Legionella enzyme Lem3. Only a short peptide sequence (eight amino acids) is required for efficient protein labeling and a small linker group (PEG‐phosphocholine) is introduced to attach the conjugated cargo. 相似文献
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Luisa Pieroni Federica Iavarone Alessandra Olianas Viviana Greco Claudia Desiderio Claudia Martelli Barbara Manconi Maria Teresa Sanna Irene Messana Massimo Castagnola Tiziana Cabras 《Journal of separation science》2020,43(1):313-336
More than 300 different protein post‐translational modifications are currently known, but only a few have been extensively investigated because modified proteoforms are commonly present in sub‐stoichiometry amount. For this reason, improvement of specific enrichment techniques is particularly useful for the proteomic characterization of post‐translationally modified proteins. Enrichment proteomic strategies could help the researcher in the challenging issue to decipher the complex molecular cross‐talk existing between the different factors influencing the cellular pathways. In this review the state of art of the platforms applied for the enrichment of specific and most common post‐translational modifications, such as glycosylation and glycation, phosphorylation, sulfation, redox modifications (i.e. sulfydration and nitrosylation), methylation, acetylation, and ubiquitinylation, are described. Enrichments strategies applied to characterize less studied post‐translational modifications are also briefly discussed. 相似文献
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Tom H. Wright Dr. M. Robert J. Vallée Prof. Benjamin G. Davis 《Angewandte Chemie (International ed. in English)》2016,55(20):5896-5903
Site‐directed (gene) mutagenesis has been the most useful method available for the conversion of one amino acid residue of a given protein into another. Until relatively recently, this strategy was limited to the twenty standard amino acids. The ongoing maturation of stop codon suppression and related technologies for unnatural amino acid incorporation has greatly expanded access to nonstandard amino acids by expanding the scope of the translational apparatus. However, the necessity for translation of genetic changes restricts the diversity of residues that may be incorporated. Herein we highlight an alternative approach, termed post‐expression mutagenesis, which operates at the level of the very functional biomolecules themselves. Using the lens of retrosynthesis, we highlight prospects for new strategies in protein modification, alteration, and construction which will enable protein science to move beyond the constraints of the “translational filter” and lead to a true synthetic biology. 相似文献
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《Analytical letters》2012,45(5):725-736
Abstract This study was designed to evaluate free amino acid (FAA) composition and total protein in mature human milk from Turkish mothers. Free amino acid concentrations in mature human milk were determined in all subjects using a high‐performance liquid chromatography (HPLC) with postcolumn derivatization system, with a fluorescence detector. Total protein content was determined by the classical biuret method. Total protein concentration was found to be 1.3±0.4 mg/dl. Glutamic asid plus glutamine is the most abundant amino acid (1275 µmol/L), followed by taurine (353 µmol/L) and alanine (261 µmol/L). Glutamic acid plus glutamine accounts for the most free amino acids in mature human milk and their sum represents 40% of total FAA. On the other hand, some amino acid derivatives such as citrulline, ethanolamine, ammonium, ornithine, ortophosphoserine, and phosphoethanolamine, not usually a part of protein, are determined and this fraction represented ~21% of the total FAA in mature human milk in the present study. 相似文献
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天然蛋白质由20种天然氨基酸组成,这些蛋白质的构筑基元包含功能基团:羧基、氨基、巯基、硫醚、羟基、碱性胺、烷基和芳基。然而,这些有限的功能基团却不足以完成生物体内所有的生物学功能。为了更好地让生命的体现者--蛋白质完成更加精确和多样的生物学功能,自然界会对蛋白质进行翻译后的修饰,包括:磷酸化,甲基化,乙酰化或者羟基化,甚至在某些情况下,进化出一种新型的翻译机制以便插入硒代半胱氨酸或者吡咯霉素。受此启发,生物化学家发展出各种生物或化学方法来改变或插入新的蛋白质构筑基元,使天然蛋白质完成其相应的生物学功能或者使其具有某些特殊的性质,甚至是创造一种新酶。该文将简单介绍这些蛋白质修饰策略以及该领域的最新进展。 相似文献
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The possibility of preparing feed from wheat straw via fermentation by cellulolytic enzymes from the fungusTrichoderma harzianumis demonstrated. The water- and salt-soluble fractions of the fermented feed contain the largest quantity of essential amino acids (22.93%). The predominant essential amino acids are lysine, leucine, methionine, and threonine. The total essential amino acids in the water- and salt-soluble fractions represent 31.44% of the total amount of protein in the fermented feed 相似文献
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The biosynthesis of protein biomass of the fungus Penicillium atrovenetum on substrates containing cellulose was studied. It was found that protein formation depends on the substrate and its content in the culture medium. The largest amount of protein biomass (16.4%) as a carbon source was produced by cultivating fungus on corn stalks ground to a particle size of 90 m. Investigation of the fractional composition of P. atrovenetum protein biomass showed that 36.2% of it is formed in the water-soluble fraction during the exponential growth phase. The total amino-acid content was greatest in the albumin fraction (26.40%). 相似文献
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Isoxazole‐Derived Amino Acids are Bromodomain‐Binding Acetyl‐Lysine Mimics: Incorporation into Histone H4 Peptides and Histone H3 下载免费PDF全文
Angelina R. Sekirnik David S. Hewings Natalie H. Theodoulou Lukass Jursins Katie R. Lewendon Laura E. Jennings Timothy P. C. Rooney Tom D. Heightman Stuart J. Conway 《Angewandte Chemie (International ed. in English)》2016,55(29):8353-8357
A range of isoxazole‐containing amino acids was synthesized that displaced acetyl‐lysine‐containing peptides from the BAZ2A, BRD4(1), and BRD9 bromodomains. Three of these amino acids were incorporated into a histone H4‐mimicking peptide and their affinity for BRD4(1) was assessed. Affinities of the isoxazole‐containing peptides are comparable to those of a hyperacetylated histone H4‐mimicking cognate peptide, and demonstrated a dependence on the position at which the unnatural residue was incorporated. An isoxazole‐based alkylating agent was developed to selectively alkylate cysteine residues in situ. Selective monoalkylation of a histone H4‐mimicking peptide, containing a lysine to cysteine residue substitution (K12C), resulted in acetyl‐lysine mimic incorporation, with high affinity for the BRD4 bromodomain. The same technology was used to alkylate a K18C mutant of histone H3. 相似文献
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Heme proteins are among the most abundant and important metalloproteins, exerting diverse biological functions including oxygen transport, small molecule sensing, selective C? H bond activation, nitrite reduction, and electron transfer. Rational heme protein designs focus on the modification of the heme‐binding active site and the heme group, protein hybridization and domain swapping, and de novo design. These strategies not only provide us with unique advantages for illustrating the structure–property–reactivity–function (SPRF) relationship of heme proteins in nature but also endow us with the ability to create novel biocatalysts and biosensors. 相似文献
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Prof. Stefano Gianni Dr. Michelle E. McCully Dr. Francesca Malagrinò Dr. Daniela Bonetti Dr. Alfonso De Simone Prof. Maurizio Brunori Prof. Valerie Daggett 《Angewandte Chemie (International ed. in English)》2018,57(39):12795-12798
Metamorphic proteins are biomolecules prone to adopting alternative conformations. Because of this feature, they represent ideal systems to investigate the general rules allowing primary structure to dictate protein topology. A comparative molecular dynamics study was performed on the denatured states of two proteins, sharing nearly identical amino‐acid sequences (88 %) but different topologies, namely an all‐α‐helical bundle protein named GA88 and an α+β‐protein named GB88. The analysis allowed successful design of and experimental validation of a site‐directed mutant that promotes, at least in part, the switch in folding from GB88 to GA88. The mutated position, in which a glutamic acid was replaced by a glutamine, does not make any intramolecular interactions in the native state of GA88, such that its stabilization can be explained by considering the effects on the denatured state. The results represent a direct demonstration of the role of the denatured state in sculpting native structure. 相似文献
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