scholarly journals Cysteine Mediated Formation of N-&epsilon -Carboxymethyllysine (CML) on Proteins

2009 ◽  
Vol 27 (Special Issue 1) ◽  
pp. S156-S159
Author(s):  
U. Schwarzenbolz ◽  
T. Henle
Keyword(s):  
Amino Acids ◽  
Maillard Reaction ◽  
Reaction System ◽  
Lysine Content ◽  
Beta Casein ◽  
Arginine Residues ◽  
Beta Lactoglobulin ◽  
Β Lactoglobulin

The reaction of glyoxal with nucleophilic amino acids was monitored for β-casein as well as β-lactoglobulin. As predicted from previous experiments with hippuryl amino acids, a measurable decrease of arginine can be found in the thiol-free β-casein, while the lysine content remained almost unchanged. For β-lactoglobulin, the incubation with glyoxal led to a slight decrease in the lysine content, while the arginine residues remained unmodified. Here, in accordance with nucleophilicity, it is suggested, that mainly cystein residues react with glyoxal. In solutions containing β-casein with or without glutathione, the effects were less pronounced and regarding the lysine and arginine content, the influence of thiols could hardly be recorded on a significant level. However, comparing the CML levels in the different incubations, it becomes obvious, that glutathione is favouring CML formation in a concentration depended manner. Therefore, the use of CML as an indicator, e.g. for the Maillard reaction, must be related to the composition of the reaction system.

scholarly journals Incorporation of alternative amino acids into cyanophycin by different cyanophycin synthetases heterologously expressed in Corynebacterium glutamicum

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ramona Wördemann ◽  
Lars Wiefel ◽  
Volker F. Wendisch ◽  
Alexander Steinbüchel
Keyword(s):  
Amino Acids ◽  
Dry Weight ◽  
Growth Conditions ◽  
Amino Acid Biosynthesis ◽  
Water Soluble ◽  
Lysine Content ◽  
Polyaspartic Acid ◽  
Acid Biosynthesis ◽  
Cyanophycin Synthetase ◽  
Potential Precursor

AbstractCyanophycin (multi-l-arginyl-poly-l-aspartic acid; also known as cyanophycin grana peptide [CGP]) is a biopolymer that could be used in various fields, for example, as a potential precursor for the synthesis of polyaspartic acid or for the production of CGP-derived dipeptides. To extend the applications of this polymer, it is therefore of interest to synthesize CGP with different compositions. A recent re-evaluation of the CGP synthesis in C. glutamicum has shown that C. glutamicum is a potentially interesting microorganism for CGP synthesis with a high content of alternative amino acids. This study shows that the amount of alternative amino acids can be increased by using mutants of C. glutamicum with altered amino acid biosynthesis. With the DM1729 mutant, the lysine content in the polymer could be increased up to 33.5 mol%. Furthermore, an ornithine content of up to 12.6 mol% was achieved with ORN2(Pgdh4). How much water-soluble or insoluble CGP is synthesized is strongly related to the used cyanophycin synthetase. CphADh synthesizes soluble CGP exclusively. However, soluble CGP could also be isolated from cells expressing CphA6308Δ1 or CphA6308Δ1_C595S in addition to insoluble CGP in all examined strains. The point mutation in CphA6308Δ1_C595S partially resulted in a higher lysine content. In addition, the CGP content could be increased to 36% of the cell dry weight under optimizing growth conditions in C. glutamicum ATCC13032. All known alternative major amino acids for CGP synthesis (lysine, ornithine, citrulline, and glutamic acid) could be incorporated into CGP in C. glutamicum.

scholarly journals Bayesian Network Analysis of Lysine Biosynthesis Pathway in Rice

Inventions ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 37
Author(s):  
Aditya Lahiri ◽  
Khushboo Rastogi ◽  
Aniruddha Datta ◽  
Endang M. Septiningsih
Keyword(s):  
Amino Acids ◽  
Reporter Gene ◽  
Nacl Stress ◽  
Stress Conditions ◽  
Lysine Biosynthesis ◽  
Model Parameters ◽  
Saline Stress ◽  
Lysine Content ◽  
Biosynthesis Pathway ◽  
Healthy Functioning

Lysine is the first limiting essential amino acid in rice because it is present in the lowest quantity compared to all the other amino acids. Amino acids are the building block of proteins and play an essential role in maintaining the human body’s healthy functioning. Rice is a staple food for more than half of the global population; thus, increasing the lysine content in rice will help improve global health. In this paper, we studied the lysine biosynthesis pathway in rice (Oryza sativa) to identify the regulators of the lysine reporter gene LYSA (LOC_Os02g24354). Genetically intervening at the regulators has the potential to increase the overall lysine content in rice. We modeled the lysine biosynthesis pathway in rice seedlings under normal and saline (NaCl) stress conditions using Bayesian networks. We estimated the model parameters using experimental data and identified the gene DAPF(LOC_Os12g37960) as a positive regulator of the lysine reporter gene LYSA under both normal and saline stress conditions. Based on this analysis, we conclude that the gene DAPF is a potent candidate for genetic intervention. Upregulating DAPF using methods such as CRISPR-Cas9 gene editing strategy has the potential to upregulate the lysine reporter gene LYSA and increase the overall lysine content in rice.

scholarly journals Effect of free amino acids and peptide hydrolysates from sunflower seed protein on the formation of pyrazines under different heating conditions

RSC Advances ◽  
2021 ◽  
Vol 11 (45) ◽  
pp. 27772-27781
Author(s):  
Furong Wang ◽  
Hailiang Shen ◽  
Xi Yang ◽  
Ting Liu ◽  
Yali Yang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Maillard Reaction ◽  
Free Amino Acids ◽  
Free Amino ◽  
Sunflower Seed ◽  
Seed Protein ◽  
Heating Temperature ◽  
Reaction Model

Exploring the effect of heating temperature and time on the formation of pyrazines; revealing the potential roles of FAAs and hydrolyzed sunflower seed peptides in the Maillard reaction model.

scholarly journals Genetic polymorphism of milk protein loci in Argentinian Holstein cattle

2000 ◽  
Vol 23 (4) ◽  
pp. 819-823 ◽  
Author(s):  
Adriana Gloria Bonvillani ◽  
Miguel Angel Di Renzo ◽  
Iván Nicolás Tiranti
Keyword(s):  
Genetic Polymorphism ◽  
Milk Protein ◽  
Genotypic Diversity ◽  
Genetic Distances ◽  
Holstein Cattle ◽  
Starch Gel Electrophoresis ◽  
Beta Casein ◽  
Hardy Weinberg Equilibrium ◽  
Quality Of Milk ◽  
Beta Lactoglobulin

Some alleles of milk protein loci are associated with superior cheese production characteristics. The genetic polymorphism of the milk protein loci alphas1-casein, beta-casein, k-casein and beta-lactoglobulin was examined in Argentinian Holstein cattle. Samples from 12 herds of four regions of Córdoba were analyzed by starch gel electrophoresis. The chi² test was used to assess whether the populations were in Hardy-Weinberg equilibrium. Genotypic diversity was analyzed by the Shannon-Weaver index. The observed genotypic frequencies were analyzed by Hedrick's genetic identity and the genetic distance of Balakrishnan and Sanghvi. The allelic and genotypic frequencies were similar to those of other Holstein populations. The genotypic frequencies of the alphas1-casein and beta-casein loci were in equilibrium, whereas in some populations the k-casein and beta-lactoglobulin loci were not. According to the Shannon-Weaver index the total genetic diversity within each herd was greater than 96%. The high values of identity agreed with the low genetic distances among populations. We conclude that there is extensive genetic homogeneity in Holstein cattle in Córdoba Province and that it would be feasible to select for B alleles at the k-casein and b-lactoglobulin loci in order to improve the quality of milk available for cheese manufacturing.

scholarly journals WRAP-based nanoparticles for siRNA delivery: a SAR study and a comparison with lipid-based transfection reagents

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Karidia Konate ◽  
Emilie Josse ◽  
Milana Tasic ◽  
Karima Redjatti ◽  
Gudrun Aldrian ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gene Silencing ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Sirna Delivery ◽  
Cell Penetrating Peptides ◽  
Sirna Transfection ◽  
Arginine Residues ◽  
Sar Study

AbstractRecently, we designed novel amphipathic cell-penetrating peptides, called WRAP, able to transfer efficiently siRNA molecules into cells. In order to gain more information about the relationship between amino acid composition, nanoparticle formation and cellular internalization of these peptides composed of only three amino acids (leucine, arginine and tryptophan), we performed a structure–activity relationship (SAR) study. First, we compared our WRAP1 and WRAP5 peptides with the C6M1 peptide also composed of the same three amino acids and showing similar behaviors in siRNA transfection. Afterwards, to further define the main determinants in the WRAP activity, we synthesized 13 new WRAP analogues harboring different modifications like the number and location of leucine and arginine residues, the relative location of tryptophan residues, as well as the role of the α-helix formation upon proline insertions within the native WRAP sequence. After having compared the ability of these peptides to form peptide-based nanoparticles (PBNs) using different biophysical methods and to induce a targeted gene silencing in cells, we established the main sequential requirements of the amino acid composition of the WRAP peptide. In addition, upon measuring the WRAP-based siRNA transfection ability into cells compared to several non-peptide transfection agents available on the markets, we confirmed that WRAP peptides induced an equivalent level of targeted gene silencing but in most of the cases with lower cell toxicity as clearly shown in clonogenic assays.

EFFECT OF VARIETY AND GROWING CONDITIONS ON THE PROTEIN AND AMINO ACID COMPOSITION OF RAPESEED

1963 ◽  
Vol 43 (1) ◽  
pp. 65-67 ◽  
Author(s):  
D. R. Clandinin ◽  
Louise Bayly
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Protein Content ◽  
Essential Amino Acids ◽  
Lysine Content ◽  
Amino Acid Distribution ◽  
Cent Level ◽  
Growing Conditions ◽  
Polish Variety

The protein content and the distribution of essential amino acids in the protein of six varieties or strains of rapeseed grown at three widely separated locations in Alberta, Beaverlodge, Edmonton and Lethbridge, were studied. Differences in protein content and amino acid distribution in the protein of the seed attributable to varietal or strain effects were noted. Turkish and Polish rapeseed were significantly lower in protein content than rapeseed of the Argentine variety. The Argentine variety and the two strains of Argentine-type studied were significantly lower in lysine than the Polish variety. Station differences in protein content approached significance at the 5 per cent level while location had a highly significant effect on the lysine content of the protein of the seed and significant effects on the histidine, arginine, phenylalanine and leucine content.

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