scholarly journals Recovery of Gelatin from Bovine Skin with the Aid of Pepsin and Its Effects on the Characteristics of the Extracted Gelatin

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1554
Author(s):  
Tanbir Ahmad ◽  
Amin Ismail ◽  
Siti Aqlima Ahmad ◽  
Khalilah Abdul Khalil ◽  
Elmutaz Atta Awad ◽  
...  

Pepsin enzyme was used to pretreat the bovine skin at the rate of 5, 15, and 25 units of enzyme/g of skin to recover gelatin, and the recovered gelatins were referred to as Pe5, Pe15, and Pe25, respectively. The gelatin yield increased significantly (p < 0.05) from 18.17% for Pe5 to 24.67% for Pe25 as the level of pepsin increased, but the corresponding gel strength and viscosity decreased significantly (p < 0.05) from 215.49 to 56.06 g and 9.17 to 8.17 mPa.s for Pe5 and Pe25, respectively. β- and α1- and α2-chains were degraded entirely in all the gelatins samples as observed in protein pattern elaborated by gel electrophoresis. 1H nuclear magnetic resonance (1H NMR) analysis indicated the coiled structure of gelatin protein chains. The lowest amide III amplitude of Pe25 as found by Fourier transform infrared (FTIR) spectroscopy indicated that α-helix structure of protein chains were lost to more irregular coiled structure. Thus, it could be summarized that pepsin might be used at the lower level (5 units/g of wet skin) to extract gelatin from bovine skin with good functional properties and at higher level (15/25 units/g of wet skin) to obtain gelatin of industrial grade with high yield.


1982 ◽  
Vol 28 (4) ◽  
pp. 890-899 ◽  
Author(s):  
R P Tracy ◽  
R M Currie ◽  
D S Young

Abstract We examined sera from a normal population by two-dimensional gel electrophoresis, to establish the normal pattern of serum proteins and to investigate genetic polymorphisms. With such information in hand, specimens from patients with certain diseases may be readily evaluated. Towards this goal, we optimized the ISO-DALT system (Proc. Natl, Acad, Sci, USA 74: 5421--5425, 1977) for routine phenotyping of alpha 1-antitrypsin, haptoglobin, GC-globulin, alpha 2-HS-glycoprotein, and transferrin, as well as a previously unknown polymorphic protein. We examined the effects of aging the specimens for 2 h at room temperature (no changes) or at -20 degrees C for several months (small changes), as well as serum/plasma differences and the effect of protease inhibitors. Silver-stain methods were modified to allow simultaneous staining of 10 gels, with reasonably good reproducibility of stain intensity. We quantitated silver-stained gels by densitometry of photographic transparencies. Very small samples suffice with this stain (0.5 microL of serum or plasma), allowing the use of "finger-stick" methods instead of venipuncture, yet the patterns are better resolved and easier to read than those for 10-microL specimens processed on gels stained with Coomassie Blue. Our techniques for rapidly removing albumin and IgG allow the investigator to examine areas on the gel that ordinarily are obscured. The region of haptoglobin has been examined by using serum from an ahaptoglobinemic donor. Finally, we present an expanded "normal" map illustrating the composite protein pattern.



2020 ◽  
Vol 58 (4) ◽  
Author(s):  
Takeshi Nagai ◽  
Masataka Saito ◽  
Yasuhiro Tanoue ◽  
Norihisa Kai ◽  
Nobutaka Suzuki

Research background. Animal collagen has been widely utilized in foods, cosmetics, and biomedical fields. The non-edible portion, such as fish skins and bones, are generated during cooking processes. Most of them are currently discarded as wastes, although the nutritional values of the skins and bones are high. It needs to utilize the non-edible portion for the reduction of environmental impact, as it may be one of source of environmental pollution. Experimental approach. Collagen was prepared from Sakhalin taimen skins as wastes generated during cooking processes. Next, the color, SDS-polyacrylamide gel electrophoresis, ultraviolet absorption, subunit composition, amino acid composition, denaturation temperature, and attenuated total reflectance-Fourier transform infrared spectroscopy analysis were conducted to explore the properties of the collagen. Lastly, it tried to improve the functional properties of the collagen using chemical modification technique for future applications. Results and conclusions. Cold acetone treatment made it possible to easily remove the fats and pigments from skins. The odorless and pure-white collagen was obtained with high-yield. The α3 chain did not exist in the collagen. Sakhalin taimen skin collagen had rich α-helix and low β-sheet structures. Succinylation caused the secondary structural changes of the collagen molecule. Moreover, succinylation made it possible not only to increase the viscosity of collagen solution and but also to improve the solubility of collagen in the physiological conditions around pH=6. Novelty and scientific contribution. This finding was the first report on the absence of the α3 chain in Salmonid fish skin collagens. The succinylated collagen from Sakhalin taimen skins as useful biomass has potential to utilize in foods, cosmetics, and its related industries.



Biopolymers ◽  
2001 ◽  
Vol 60 (5) ◽  
pp. 366 ◽  
Author(s):  
Zhengshuang Shi ◽  
C. Anders Olson ◽  
Anthony J. Bell ◽  
Neville R. Kallenbach


1981 ◽  
Vol 197 (2) ◽  
pp. 519-522 ◽  
Author(s):  
E G Afting ◽  
M L Recker

Cathepsin D was purified by two-step affinity chromatography on concanavalin A- and pepstatin-Sepharose. The main purification was achieved by washing the enzyme bound to the pepstatin-Sepharose column with buffered 6 M-urea. This step separated cathepsin D from all low- and high-molecular-weight impurities. Although the 1700-fold purified acid proteinase was homogeneous on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, it still showed microheterogeneity.



Nutrients ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 753
Author(s):  
Benita C. Percival ◽  
Angela Wann ◽  
Richard Zbasnik ◽  
Vicki Schlegel ◽  
Mark Edgar ◽  
...  

High-resolution 1H nuclear magnetic resonance (NMR) analysis was employed to molecularly screen the lipid, lipid oxidation product (LOP), and antioxidant compositions of four natural (unrefined) cod liver oil (CLO) products. Products 1–3 were non-fermented CLOs, whilst Product 4 was isolated from pre-fermented cod livers. Supporting analytical data that were acquired included biogenic amine, flavanone, tannin, phenolic antioxidant, α-tocopherol, and oxygen radical absorbance capacity (ORAC) determinations by recommended HPLC, LC/MS/MS, or spectrophotometric methods. SDS-PAGE, HPLC, and 1H NMR analyses investigated and determined collagenous antioxidants and their molecular mass ranges. 1H NMR analysis of aldehydic LOPs was employed to explore the susceptibilities/resistivities of each CLO product to peroxidation that is induced by thermal stressing episodes (TSEs) at 180°C, or following prolonged (42 day) storage episodes at 4 and 23 °C. Product 4 displayed extremely high ORAC values, which were much greater than those of Products 1–3, and that were predominantly ascribable to significant levels of peroxidation-blocking and/or aldehyde-consuming collagenous polypeptides/peptides and ammoniacal agents therein. Significantly lower levels of toxic aldehydes were generated in the pre-fermented Product 4 during exposure to TSEs, or the above long-term storage episodes. These results confirmed the enhanced peroxidative resistivity of a fermented, antioxidant-fortified natural CLO product over those of non-fermented unrefined products. Product 4: Green Pasture Blue Ice™ Fermented Cod Liver Oil.



1995 ◽  
Vol 41 (11) ◽  
pp. 1599-1604 ◽  
Author(s):  
M K Bolla ◽  
L Haddad ◽  
S E Humphries ◽  
A F Winder ◽  
I N Day

Abstract Molecular epidemiological research has identified the association of a common apolipoprotein E (apo E) isoform (E4 as opposed to E3), with risk both of coronary artery disease and of Alzheimer dementia. In addition, the role of apo E genotype (usually E2/E2) in Type III hyperlipidemia is well known. However, both for diagnostic and research purposes, apo E genotyping is cumbersome. The preferred approach is electrophoretic sizing of restriction digestion fragments, enabling simultaneous analysis of the two codons (112 and 158) that represent the six common genotypes (E2/E2; E2/E3; E2/E4; E3/E3; E3/E4; E4/E4). However, the consequent demands of high-yield PCR, high-resolution, high-throughput electrophoresis, and sufficient detection sensitivity have left shortfalls in published protocols. In conjunction with a high-throughput electrophoresis system we described recently, microplate array diagonal gel electrophoresis (MADGE), we have constructed extensively optimized, simplified protocols for DNA isolation from mouthwash samples for PCR setup and high-yield PCR, for restriction digestion, and for subsequent MADGE gel image analysis. The integral system enables one worker to readily undertake apo E genotyping of as many as hundreds of DNA samples per day, without special equipment.



1982 ◽  
Vol 28 (4) ◽  
pp. 955-961 ◽  
Author(s):  
C S Giometti ◽  
K E Willard ◽  
N L Anderson

Abstract Differences in proteins between cells grown as suspension cultures and those grown as attached cultures were studied by comparing the proteins of detergent-resistant cytoskeletons prepared from peripheral blood leukocytes and a lymphoblastoid cell line (GM607) (both grown as suspension cultures) and those of human skin fibroblasts (grown as attached cultures) by two-dimensional gel electrophoresis. The major cytoskeletal proteins of the leukocytes were also present in the protein pattern of GM607 cytoskeletons. In contrast, the fibroblast cytoskeletal protein pattern contained four groups of proteins that differed from the patterns of the leukocytes and GM607. Three groups (Cytoskf:8--10, :14--16, and :17--18) showed qualitative differences, and the fourth group (Cytoskf:11 and :13) showed quantitative differences. In addition, surface labeling of GM607 and human fibroblasts with 125I demonstrated that substantial amounts of vimentin and actin are exposed at the surface of the attached fibroblasts, but there is little evidence of similar exposure at the surface of the suspension-grown GM607. Cytoskf:11 and :13 in fibroblast preparations were also labeled with the 125I. These results demonstrate some differences in cytoskeletal protein composition between different types of cells could be related to their ability or lack of ability to grow as attached cells in tissue culture.



1996 ◽  
Vol 44 (9) ◽  
pp. 2646-2649 ◽  
Author(s):  
Hiroya Ishikawa ◽  
Mitsuya Shimoda ◽  
Akiyoshi Yonekura ◽  
Yutaka Osajima


2008 ◽  
Vol 41 (5) ◽  
pp. 301-314 ◽  
Author(s):  
Philippa Davies ◽  
Kate Watt ◽  
Sharon M Kelly ◽  
Caroline Clark ◽  
Nicholas C Price ◽  
...  

Poly-amino acid repeats, especially long stretches of glutamine (Q), are common features of transcription factors and cell-signalling proteins and are prone to expansion, resulting in neurodegenerative diseases. The amino-terminal domain of the androgen receptor (AR-NTD) has a poly-Q repeat between 9 and 36 residues, which when it expands above 40 residues results in spinal bulbar muscular atrophy. We have used spectroscopy and biochemical analysis to investigate the structural consequences of an expanded repeat (Q45) or removal of the repeat (ΔQ) on the folding of the AR-NTD. Circular dichroism spectroscopy revealed that in aqueous solution, the AR-NTD has a relatively limited amount of stable secondary structure. Expansion of the poly-Q repeat resulted in a modest increase in α-helix structure, while deletion of the repeat resulted in a small loss of α-helix structure. These effects were more pronounced in the presence of the structure-promoting solvent trifluoroethanol or the natural osmolyte trimethylamine N-oxide. Fluorescence spectroscopy showed that the microenvironments of four tryptophan residues were also altered after the deletion of the Q stretch. Other structural changes were observed for the AR-NTDQ45 polypeptide after limited proteolysis; in addition, this polypeptide not only showed enhanced binding of the hydrophobic probe 8-anilinonaphthalene-1-sulphonic acid but was more sensitive to urea-induced unfolding. Taken together, these findings support the view that the presence and length of the poly-Q repeat modulate the folding and structure of the AR-NTD.



2000 ◽  
Vol 95 (3) ◽  
pp. 199-207 ◽  
Author(s):  
Vera Regitz-Zagrosek ◽  
Antonius Kyriakopoulos ◽  
Peter Jungblut ◽  
Dietrich Behne ◽  
Klaus-Peter Plei�ner ◽  
...  


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