scholarly journals Chemical modification of β-lactoglobulin by quinines

2003 ◽  
Vol 68 (4-5) ◽  
pp. 243-248 ◽  
Author(s):  
Irena Novakovic ◽  
Zoran Vujcic ◽  
Tatjana Bozic ◽  
Natasa Bozic ◽  
Nenad Milosavic ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Chemical Modification ◽  
Model Compound ◽  
Cow Milk ◽  
Amino Groups ◽  
Tert Butyl ◽  
Sds Page ◽  
Covalent Modifications ◽  
Β Lactoglobulin

The avarone/avarol quinone/hydroquinone couple, as well as their derivatives show considerable antitumor activity. In this work, covalent modifications of ?-lactoglobulin, isolated from cow milk, by avarone, its model compound 2-tert-butyl-1,4-benzoquinone, and several of their alkylthio derivatives were studied. The techniques applied for assaying the modifications were UV/VIS spectrophotometry, SDS PAGE and isoelectrofocusing. The results of the SDS PAGE suggest that polymerisation of the protein occurs. The shift of the pI of the protein upon modification toward lower values indicates that lysine amino groups are the principal site of the reaction of ?-lactoglobulin with the quinines.

scholarly journals Protein covalent modification of biologically active quinones

2004 ◽  
Vol 69 (11) ◽  
pp. 901-907 ◽  
Author(s):  
Dusan Sladic ◽  
Irena Novakovic ◽  
Zoran Vujcic ◽  
Tatjana Bozic ◽  
Natasa Bozic ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Chemical Modification ◽  
Covalent Modification ◽  
Biologically Active ◽  
Amino Groups ◽  
Sds Page ◽  
Protein Covalent

The avarone/avarol quinone/hydroquinone couple shows considerable antitumor activity. In this work, covalent modification of ?-lactoglobulin by avarone and its derivatives as well as by the synthetic steroidal quinone 2,5(10)-estradiene- 1,4,17-trione and its derivatives were studied. The techniques for studying chemical modification of ?-lactoglobulin by quinones were: UV/Vis spectrophotometry, SDS PAGE and isoelectrofocusing. SDS PAGE results suggest that polymerization of the protein occurs. It could be seen that the protein of 18 kD gives the bands of 20 kD, 36 kD, 40 kD, 45 kD, 64 kD and 128 kD depending on modification agent. The shift of the pI of the protein (5.4) upon modification toward lower values (from pI 5.0 to 5.3) indicated that lysine amino groups are the principal site of the reaction of ?-lactoglobulin with the quinones.

scholarly journals MAJOR GOAT MILK PROTEIN: SEPARATION AND CHARACTERIZATION BY “LAB-ON-A-CHIP” MICROFLUIDIC ELECTROPHORES

2018 ◽  
Vol 35 (2) ◽  
Author(s):  
ALESSA SIQUEIRA DE O. DOS SANTOS ◽  
VANEIDA MARIA MEURER ◽  
FABIANO FREIRE COSTA ◽  
IGOR MOURA DE PAIVA ◽  
GISELE NOGUEIRA FOGAÇA ◽  
...  
Keyword(s):  
Protein Separation ◽  
Whey Proteins ◽  
Milk Proteins ◽  
Goat Milk ◽  
Lab On A Chip ◽  
Cow Milk ◽  
Total Percentage ◽  
Chip Technology ◽  
Sds Page ◽  
Β Lactoglobulin

This work presents the electrophoretic profile of goat and cow milk samples and their mixtures using microfluidic and conventional electrophoresis. The microfluidic method allowed the separation of the major caseins from milk, excepting the goat κ-casein.  Besides, the major whey proteins were separated with perfect distinction of A and B β-lactoglobulin variants. Comparing to SDS-PAGE, a variation in the molecular weight was observed in all milk proteins. However, A and B β-lactoglobulin variants could not be isolated using SDS-PAGE. Although urea-PAGE did not show high resolution among whey proteins, γ-, κ-, β-, and α-caseins were clearly identified. This method also showed a lower limit detection of cow milk in mixture samples than the "lab-on-a-chip" electrophoresis. In both methods, the highest linearity obtained from plotting total percentage against cow milk concentration was observed by using cow αs1-casein (R2 = 0.986 and R² = 0.973). This result indicates that microfluidic electrophoresis is an effective tool to detect the presence of some proteins in goat and cow milk, and in mixtures. Microfluidic chip technology might will complement the current methods for analyzing milk proteins, highlighting its speed amount of reagents and whey protein separation, which showed a better result than urea or SDS-PAGE

Model Compound Approach for Polymer-Metal InterFaces: ESCA Studies

1984 ◽  
Vol 40 ◽  
Author(s):  
P. N. Sanda ◽  
J. W. Bartha ◽  
B. D. Silverman ◽  
P. S. Ho ◽  
A. R. Rossi
Keyword(s):  
Model Compound ◽  
Amino Groups ◽  
Ether Linkage ◽  
Cu Films ◽  
Polymer Metal ◽  
Terminal Amino ◽  
Metal Interfaces ◽  
Imide Group

AbstractESCA studies of two molecules which are similar in structure to the PMDA and ODA constituents of the PMDA-ODA polyimide monomer are discussed. Their interaction with in-situ evaporated Cr and Cu films are compared. The PMDA model compound interacts with Cr through the imide group, while very little interaction is observed with Cu. The ODA model compound (oxydianiline) interacts with Cr via the ether linkage and the terminal amino groups, whereas very little interaction is observed with Cu.

scholarly journals Chemical Modification and Antitumor Activity of Polysaccharides from the Mycelium of Liquid-cultured Grifola frondosa.

1994 ◽  
Vol 41 (10) ◽  
pp. 733-740 ◽  
Author(s):  
Cun ZHUANG ◽  
Takashi MIZUNO ◽  
Hitoshi ITO ◽  
Keishiro SHIMURA
Keyword(s):  
Antitumor Activity ◽  
Chemical Modification ◽  
Grifola Frondosa

The dynamics of individual whey protein concentrations in cows’ mammary secretions during the colostral and early lactation periods

2018 ◽  
Vol 86 (1) ◽  
pp. 88-93 ◽  
Author(s):  
Raquel F.S. Raimondo ◽  
Juliana S.P. Ferrão ◽  
Samantha I. Miyashiro ◽  
Priscila T. Ferreira ◽  
João Paulo E. Saut ◽  
...  
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Whey Proteins ◽  
Total Proteins ◽  
Mature Milk ◽  
Rennet Coagulation ◽  
Sds Page ◽  
Different Types ◽  
Biuret Method ◽  
Jersey Cows ◽  
Β Lactoglobulin

AbstractThe bovine whey consists of more than 200 different types of proteins, of which β-lactoglobulin, α-lactalbumin, serum albumin, immunoglobulins and lactoferrin predominate. However, their concentrations are not stable due to the existence of protein dynamics during a transition from colostrum secretion to mature milk. To evaluate the dynamics of whey proteins of Jersey cows during a colostral phase and first month of lactation and an influence of the number of lactations, 268 milk samples from 135 Jersey cows were selected through a clinical evaluation. Whey was obtained by rennet coagulation of the mammary secretion. The concentration of total proteins was determined by the biuret method and their fractions were identified by 12% dodecyl sulfate-polyacrylamide gel electrophoresis (12% SDS-PAGE). Maximum concentrations of all protein fractions were observed in the first 12 h of lactation, reducing over the course of the study. Modification of the protein predominance was also observed. The transition from colostrum secretion to milk occurred between 24 and 72 h postpartum. There was an influence of the number of lactations on the dynamics of whey proteins, indicating that multiparous cows had better immunological and nutritional quality when compared to primiparous cows.

Peculiarities of extraction of β-lactoglobuline in protein mineral concentrates at electroactivation of whey

2020 ◽  
Vol 2 (1) ◽  
pp. 52-68
Author(s):  
Mircea BOLOGA ◽  
Elvira VRABIE ◽  
Irina PALADII ◽  
Olga ILIASENCO ◽  
Tatiana STEPURINA ◽  
...  
Keyword(s):  
Protein Content ◽  
Whey Proteins ◽  
Sodium Dodecyl ◽  
Total Protein Content ◽  
Treatment Regimens ◽  
Sds Page ◽  
Different Types ◽  
Lower Protein ◽  
Β Lactoglobulin ◽  
Excellent Source

Introduction. Whey is a by-product and an excellent source of proteins that is rather aggressive due to a large amount of organic substances it contains. The electro-activation of whey applied in the experiments is a wasteless method that allows the va-lorification of all whey components. β-lactoglobulin (β-Lg) makes up 50% of the whey proteins and 12% of the total protein content in milk. Material and methods. The recovery of β-Lg in protein-mineral concentrates (PMC) by electro-activation processing of different types of whey with different initial protein content was investigated in seven configurations. The recovery of protein fractions in the PMCs were analyzed via electrophoresis with sodium dodecyl sulfate (SDS-PAGE) and 15% non-denaturing polyacrylamide gel (PAAG).      Results. Whey electro-fractionation and the obtaining of PMCs with predetermined protein content, namely of β-Lg, were studied on three whey types, processed at different treatment regimens and in seven configurations. The proper management of electroactivation by varying the treatment regimens will allow the electro-fractionation of different types of dairy by-products. Conclusions. The maximum amount of β-Lg recovered in PMCs on electroactivation is  66-71% depending on the processed whey and on the treatment regimens. Obviously, the extraction of β-Lg from initially lower protein content shows a higher recovery degree of β-Lg. The registered temperatures allows formation of PMCs without thermal denaturation.

scholarly journals Sulfonation and Characterization of Tert-Butyl Styrene/Styrene/Isoprene Copolymer and Polypropylene Blends for Blood Compatibility Applications

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1351
Author(s):  
Bin-Hong Tsai ◽  
Yung-Han Chuang ◽  
Chi-Hui Cheng ◽  
Jui-Che Lin
Keyword(s):  
Block Copolymers ◽  
Chemical Modification ◽  
Blood Compatibility ◽  
Blood Platelet ◽  
Mineral Oil ◽  
Tert Butyl ◽  
Hydrophobic Nature ◽  
Polypropylene Blends ◽  
Uv Ozone

Hydrogenated styrenic block copolymers (HSBCs) have been used in medical tubing for many years due to their high clarity, flexibility, kink resistance, and toughness. However, when it comes to blood storage applications, HSBC compounds’ market has been limited because of their high hydrophobicity, which may trigger platelet adhesion when contacting with blood. HSBC needs to be physically or chemically modified in advance to make it blood compatible; however, HSBC has strong UV/ozone resistance, thermooxidative stability, and excellent processing capability, which increases the difficulty of the chemical modification process as unsaturated dienes has been converted to saturated stable midblocks. Moreover, medical HSBC-containing compounds primarily make up with the non-polar, hydrophobic nature and benign characteristics of other common ingredients (U.S. Pharmacopeia (USP) grades of mineral oil and polypropylene), which complicates the realization of using HSBC-containing compounds in blood-contacting applications, and this explains why few studies had disclosed chemical modification for biocompatibility improvement on HSBC-containing compounds. Sulfonation has been reported as an effective way to improve the material’s blood/platelet compatibility. In this study, hydrogenated tert-butyl styrene (tBS)-styrene-isoprene block copolymers were synthesized and its blends with polypropylene and USP grades of mineral oil were selectively sulfonated by reaction with acetyl sulfate. By controlling the ratio of the hydrogenated tBS-styrene-isoprene block copolymer in the blend, sulfonated films were optimized to demonstrate sufficient physical integrity in water as well as thermal stability, hydrophilicity, and platelet compatibility.

scholarly journals Chemical modification of the adeno-associated virus capsid to improve gene delivery

2020 ◽  
Vol 11 (4) ◽  
pp. 1122-1131 ◽  
Author(s):  
Mathieu Mével ◽  
Mohammed Bouzelha ◽  
Aurélien Leray ◽  
Simon Pacouret ◽  
Mickael Guilbaud ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Chemical Modification ◽  
Neutralizing Antibodies ◽  
Cell Tropism ◽  
Amino Groups ◽  
Chemical Modifications ◽  
Virus Capsid ◽  
Adeno Associated Virus

Bioconjugated AAV vectors, achieved by coupling of ligands on amino groups of the capsid, are of great interest for gene delivery. Chemical modifications can be used to enhance cell tropism and to decrease interactions with neutralizing antibodies.

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