The relationship between acrylamide and various components during coffee roasting and effect of amino acids on acrylamide formation

Author(s):  
Huihui Hu ◽  
Xiaoling Liu ◽  
Lian Jiang ◽  
Qi Zhang ◽  
Haide Zhang
2019 ◽  
Vol 20 (7) ◽  
pp. 644-651 ◽  
Author(s):  
Changsong Gu ◽  
Xiangbing Mao ◽  
Daiwen Chen ◽  
Bing Yu ◽  
Qing Yang

Branched chain amino acids are the essential nutrients for humans and many animals. As functional amino acids, they play important roles in physiological functions, including immune functions. Isoleucine, as one of the branched chain amino acids, is also critical in physiological functions of the whole body, such as growth, immunity, protein metabolism, fatty acid metabolism and glucose transportation. Isoleucine can improve the immune system, including immune organs, cells and reactive substances. Recent studies have also shown that isoleucine may induce the expression of host defense peptides (i.e., β-defensins) that can regulate host innate and adaptive immunity. In addition, isoleucine administration can restore the effect of some pathogens on the health of humans and animals via increasing the expression of β-defensins. Therefore, the present review will emphatically discuss the effect of isoleucine on immunity while summarizing the relationship between branched chain amino acids and immune functions.


1984 ◽  
Vol 38 (2) ◽  
pp. 177-179 ◽  
Author(s):  
B.S. Chauhan ◽  
N.C. Desai ◽  
Ramesh Bhatnagar ◽  
S.P. Garg

2021 ◽  
Vol 79 (11) ◽  
pp. 1372
Author(s):  
Zhao Zhao ◽  
Shiwen Cheng ◽  
Yuezhong Mao ◽  
Jianxi Ying ◽  
Shiyi Tian ◽  
...  

Author(s):  
Mark Lorch

This chapter examines proteins, the dominant proportion of cellular machinery, and the relationship between protein structure and function. The multitude of biological processes needed to keep cells functioning are managed in the organism or cell by a massive cohort of proteins, together known as the proteome. The twenty amino acids that make up the bulk of proteins produce the vast array of protein structures. However, amino acids alone do not provide quite enough chemical variety to complete all of the biochemical activity of a cell, so the chapter also explores post-translation modifications. It finishes by looking as some dynamic aspects of proteins, including enzyme kinetics and the protein folding problem.


Author(s):  
Frank E. Scully, Jr ◽  
Barbara Conyers

Over the past 20 years, gas chromatography/mass spectroscopy (GC/MS) has been widely used to identify trace organic environmental contaminants and to study the mechanisms of the formation or transformation of organic compounds either by natural or man-made processes. In the area of water and wastewater disinfection, GC/MS has been highly successful in identifying numerous volatile organic chlorination by-products, some of which may pose undesirable health risks to humans and aquatic organisms at concentrations found in some waters. However, despite a considerable amount of research in this area much of the chemistry continues to be poorly understood. Analysis of trace organics by GC/MS relies on the assumption that the compounds to be analyzed are (1) volatile and (2) thermally stable to GC temperatures as high as 300 °C. Because nuclear magnetic resonance spectroscopy (NMR) is a mild and nondestructive method of analysis, it can reveal reactions that occur in water that cannot be observed by GC/MS. Until recently the reactions of amino acids with two or more equivalents of aqueous chlorine were believed to produce aldehydes and nitriles according to equation (1). LeCloirec and Martin have reported that the formation of nitriles in such situations may come in part from the reaction of monochloramine with aldehydes (equation (2)). Because reaction (2) may affect the distribution of products in reaction (1), it was important to determine the relationship between these two reactions. This chapter will review the applications of NMR we have used in studies of the products formed upon chlorination of amino acids.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Duan Chu ◽  
Lai Wei

Abstract Background Synonymous mutations do not change amino acids but do sometimes change the tRNAs (anticodons) that decode a particular codon. An isoaccepting codon is a synonymous codon that shares the same tRNA. If a mutated codon could base pair with the same anticodon as the original, the mutation is termed an isoaccepting mutation. An interesting but less-studied type of codon bias is codon co-occurrence bias. There is a trend to cluster the isoaccepting codons in the genome. The proposed advantage of codon co-occurrence bias is that the tRNA released from the ribosome E site could be quickly recharged and subsequently decode the following isoaccepting codons. This advantage would enhance translation efficiency. In plant species, whether there are signals of positive selection on isoaccepting mutations in the codon co-occurred regions has not been studied. Results We termed polymorphic mutations in coding regions using publicly available RNA-seq data in maize (Zea mays). Next, we classified all synonymous mutations into three categories according to the context, i.e., the relationship between the focal codon and the previous codon, as follows: isoaccepting, nonisoaccepting and nonsynonymous. We observed higher fractions of isoaccepting mutations in the isoaccepting context. If we looked at the minor allele frequency (MAF) spectrum, the isoaccepting mutations have a higher MAF in the isoaccepting context than that in other regions, and accordingly, the nonisoaccepting mutations have a higher MAF in the nonisoaccepting context. Conclusion Our results indicate that in regions with codon co-occurrence bias, natural selection maintains this pattern by suppressing the nonisoaccepting mutations. However, if the consecutive codons are nonisoaccepting, mutations tend to switch these codons to become isoaccepting. Our study demonstrates that the codon co-occurrence bias in the maize genome is selectively maintained by natural selection and that the advantage of this trend could potentially be the rapid recharging and reuse of tRNAs to increase translation efficiency.


Author(s):  
Mohammad Rizki Fadhil Pratama ◽  
Tutus Gusdinar

Objectives: This study aims to find the relationship between artemisinins and neuraminidase (NA) with molecular docking study and also to determine the most potent NA inhibitor from artemisinin and derivatives.Methods: All ligands were sketched and optimized using Gaussian 03W with Hartree-Fock method basis sets 6-311G. Molecular docking was performed using AutoDock 4.2.3 toward NA in complexes with oseltamivir as co-crystal ligand. The main parameters used were the free energy of binding (ΔG) and dissociation constant (Ki) as affinity marker.Results: Artesunate provided most negative free ΔG and lowest Ki toward NA with −9.55 kcal/mol and 100.66 nM, respectively. Artesunate shows higher affinity than oseltamivir with interactions between artesunate and amino acids at position 246 had important influences on artesunate affinity toward NA from H5N1.Conclusion: In silico molecular docking results indicated that artesunate could be considered as NA inhibitor and should be potential to be developed as anti-influenza particularly to H5N1 with oseltamivir resistance.


Author(s):  
Andrea L. Darling ◽  
D. Joe Millward ◽  
Susan A. Lanham-New

The present paper reviews published literature on the relationship between dietary protein and bone health. It will include arguments both for and against the anabolic and catabolic effects of dietary protein on bone health. Adequate protein intake provides the amino acids used in building and maintaining bone tissue, as well as stimulating the action of insulin-like growth factor 1, which in turn promotes bone growth and increases calcium absorption. However, the metabolism of dietary sulphur amino acids, mainly from animal protein, can lead to increased physiological acidity, which may be detrimental for bone health in the long term. Similarly, cereal foods contain dietary phytate, which in turn contains phosphate. It is known that phosphate consumption can also lead to increased physiological acidity. Therefore, cereal products may produce as much acid as do animal proteins that contain sulphur amino acids. The overall effect of dietary protein on physiological acidity, and its consequent impact on bone health, is extremely complex and somewhat controversial. The consensus is now moving towards a synthesised approach. Particularly, how anabolic and catabolic mechanisms interact; as well as how the context of the whole diet and the type of protein consumed is important.


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