scholarly journals An Effective Method of Isolating Honey Proteins

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2399 ◽  
Author(s):  
Aleksandra Bocian ◽  
Justyna Buczkowicz ◽  
Marcin Jaromin ◽  
Konrad Kamil Hus ◽  
Jaroslav Legáth
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Gel Electrophoresis ◽  
Free Amino ◽  
Polyacrylamide Gel Electrophoresis ◽  
Pollen Grains ◽  
Distilled Water ◽  
Protein Isolation ◽  
Saturated Phenol

Honey is a natural sweetener composed mostly of sugars, but it contains also pollen grains, proteins, free amino acids, and minerals. The amounts and proportions of these components depend on the honey type and bee species. Despite the low content of honey protein, they are becoming a popular study object, and have recently been used as markers of the authenticity and quality of honey. Currently, the most popular methods of protein isolation from honey are dialysis against distilled water, lyophilization of dialysate, or various precipitation protocols. In this work, we propose a new method based on saturated phenol. We tested it on three popular polish honey types and we proved its compatibility with both 1D and 2D polyacrylamide gel electrophoresis (PAGE) and MS (mass spectrometry) techniques. The elaborated technique is also potentially less expensive and less time-consuming than other previously described methods, while being equally effective.

Free active peptidases are detected in Emmental juice extracted before ripening in the warm room

1998 ◽  
Vol 65 (1) ◽  
pp. 119-128 ◽  
Author(s):  
VALERIE GAGNAIRE ◽  
SYLVIE LORTAL ◽  
JOELLE LEONIL
Keyword(s):  
Amino Acids ◽  
Gel Electrophoresis ◽  
Free Amino Acids ◽  
Free Amino ◽  
Polyacrylamide Gel Electrophoresis ◽  
Peptidase Activity ◽  
Continuous Increase ◽  
Cheese Ripening ◽  
Emmental Cheese ◽  
Warm Room

In Swiss-type cheese such as Emmental, proteolysis is one of the major phenomena occurring during ripening. Among the proteolytic agents involved in cheese ripening, the free enzymes originally present in milk and those arising from bacterial autolysis can act directly on the casein network. In order to understand the contribution of the bacterial enzymes and especially those arising from the thermophilic starters, the juice of an Emmental cheese entering the warm room was extracted by pressure, then sterilized by filtration and incubated at 24°C for 20 d under anaerobiosis. At different times, the peptides and free amino acids were determined in the sterile cheese juice. In parallel, in order to gather information about the nature of the enzymes present, the sterile juice was also incubated with β-naphthylamide derivatives as substrates. We have demonstrated a continuous increase in free NH2 groups and in free amino acids throughout the 20 d incubation time. The main peptidase activity was due to aminopeptidase(s) and X-prolyldipeptidyl aminopeptidase(s) whose activities were recovered after non-denaturing polyacrylamide gel electrophoresis. Most of the enzymes found in the juice would have their origin in thermophilic starters. As they are generally intracellularly located, their release could be explained by the autolysis of these starters. Finally, the main free amino acids released in the juice (Pro, Glu, Ala, Val, Leu and Lys) corresponded to those previously found in Emmental cheese, suggesting that the enzymes detected in this study participate significantly in peptide degradation during ripening.

scholarly journals Magnesium Supplementation Alters Leaf Metabolic Pathways for Higher Flavor Quality of Oolong Tea

Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 120 ◽  
Author(s):  
Jiuliang Xu ◽  
Liangquan Wu ◽  
Bingxin Tong ◽  
Jiaxu Yin ◽  
Zican Huang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
High Resolution Mass Spectrometry ◽  
Southern China ◽  
Substantial Reduction ◽  
Sugar Accumulation ◽  
Limiting Factor ◽  
Oolong Tea

Oolong tea, one of the most famous tea beverages in China, contains specialized metabolites contributing to rich flavors and human health. Accumulation patterns of such metabolites and underlying regulatory mechanisms significantly vary under different growth conditions. To optimize quality and yield while minimizing environmental effects, three treatments were designed in this study: Conventional fertilization, optimized fertilization, and optimized fertilization supplemented with magnesium (Mg). We investigated the yield, taste quality, primary and secondary metabolites of oolong tea, and found that a substantial reduction in chemical fertilizers (nutrient optimization by reducing 43% N, 58% P2O5 and 55% K2O) did not affect the tea yield in this study. Interestingly, Mg fertilization is an important factor influencing amino acid and sugar accumulation in oolong tea, resulting in higher concentrations of total free amino acids and a lower ratio of tea polyphenols (TP) to free amino acids (FAA). Gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) and liquid chromatography-high resolution mass spectrometry (LC-HRMS) combined multivariate analyses revealed distinct features of metabolite accumulation in leaves of three different treatments, as indicated by 34 differentially accumulated characteristic compounds. The levels of serine, aspartic acid, isoleucine, phenylalanine, theanine, and proline were reduced by fertilizer optimization and increased by Mg supplementation. Mg particularly promoted theanine accumulation favoring a stronger umami taste of oolong tea, while decreasing astringency and bitter metabolites. Thus, Mg application paves a new path for tea quality improvement in Southern China where Mg deficiency in the soil is a frequent limiting factor for crop production.

scholarly journals Determination of free amino acids in plants by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS)

2015 ◽  
Vol 7 (18) ◽  
pp. 7574-7581 ◽  
Author(s):  
Magdalena M. Dziągwa-Becker ◽  
Jose M. Marin Ramos ◽  
Jakub K. Topolski ◽  
Wiesław A. Oleszek
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Liquid Chromatography ◽  
Amino Acid ◽  
Tandem Mass Spectrometry ◽  
Free Amino ◽  
Tandem Mass ◽  
Amino Acid Determination ◽  
Acid Determination

Free amino acid determination in plants by LC-MS/MS.

Polyacrylamide Gel Electrophoresis without a Stacking Gel: Use of Amino Acids as Electrolytes

2001 ◽  
Vol 291 (2) ◽  
pp. 300-303 ◽  
Author(s):  
Taeho Ahn ◽  
Sung-Kun Yim ◽  
Ho-Il Choi ◽  
Chul-Ho Yun
Keyword(s):  
Amino Acids ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Polyacrylamide Gel

scholarly journals Characterization of [3H]palmitate- and [3H]ethanolamine-labelled proteins in the multicellular parasitic trematode Schistosoma mansoni

1988 ◽  
Vol 254 (2) ◽  
pp. 419-426 ◽  
Author(s):  
P M Wiest ◽  
E J Tisdale ◽  
W L Roberts ◽  
T L Rosenberry ◽  
A A F Mahmoud ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Molecular Mass ◽  
Gel Electrophoresis ◽  
Free Amino ◽  
Protein Modification ◽  
Polyacrylamide Gel Electrophoresis ◽  
Gel Filtration ◽  
Reductive Methylation ◽  
Amide Linkage

Biosynthetic labelling experiments with cercariae and schistosomula of the multicellular parasitic trematode Schistosoma mansoni were performed to determine whether [3H]palmitate or [3H]ethanolamine was incorporated into proteins. Parasites incorporated [3H]palmitate into numerous proteins, as judged by SDS/polyacrylamide-gel electrophoresis and fluorography. The radiolabel was resistant to extraction with chloroform, but sensitive to alkaline hydrolysis, indicating the presence of an ester bond. Further investigation of the major 22 kDa [3H]palmitate-labelled species showed that the label could be recovered in a Pronase fragment which bound detergent and had an apparent molecular mass of 1200 Da as determined by gel filtration on Sephadex LH-20. Schistosomula incubated with [3H]ethanolamine for up to 24 h incorporated this precursor into several proteins; labelled Pronase fragments recovered from the three most intensely labelled proteins were hydrophilic and had a molecular mass of approx. 200 Da. Furthermore, reductive methylation of such fragments showed that the [3H]ethanolamine bears a free amino group, indicating the lack of an amide linkage. We also evaluated the effect of phosphatidylinositol-specific phospholipase C from Staphylococcus aureus: [3H]palmitate-labelled proteins of schistosomula and surface-iodinated proteins were resistant to hydrolysis with this enzyme. In conclusion, [3H]palmitate and [3H]ethanolamine are incorporated into distinct proteins of cercariae and schistosomula which do not bear glycophospholipid anchors. The [3H]ethanolamine-labelled proteins represent a novel variety of protein modification.

Study on Degradation of Radix Isatidis Polypeptide in Artificial Gastrointestinal Environment

2014 ◽  
Vol 989-994 ◽  
pp. 1020-1024
Author(s):  
Nan Nan ◽  
Xi Jing Liu
Keyword(s):  
Gel Electrophoresis ◽  
Free Amino ◽  
High Performance ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Radix Isatidis ◽  
Sds Page ◽  
Electrophoresis Method ◽  
Amino Acid Levels ◽  
Different Molecular Weight

Radix Isatidis is a traditional Chinese medicine for treatment of influenza and inflammation in China. In this paper, in order to study the degradation situation of Radix Isatidis polypeptide in artificial gastrointestinal environment, the SDS-PAGE (Sodium dodecyl sulfate-polyacrylamide gel electrophoresis) method was used to detect the degradation of Radix Isatidis polypeptide in artificial intestinal juice and gastric juice, and it showed that Radix Isatidis peptides could be degradated to different degrees. HPLC (High Performance Liquid Chromatography) was used to determine the change of peptides degradation, and it indicated that free amino acid levels did not change significantly. The result after degradation was also detected by BCA method, and it showed that there were still a large number of polypeptides in the liquid. From this experiment we can come to this conclusion that Radix Isatidis polypeptides in artificial gastrointestinal juice mostly degraded into a series of different molecular weight peptides.

Sign in / Sign up

Export Citation Format

Share Document