The yield of peptides and amino acids following acid hydrolysis of haemoglobin from porcine blood

2012 ◽  
Vol 52 (5) ◽  
pp. 313 ◽  
Author(s):  
Carlos Alvarez ◽  
Manuel Rendueles ◽  
Mario Diaz

Animal blood is the most important waste product from the meat industry due to the huge volumes produced and its pollutant power. Different methods are currently employed to process this by-product, such as drying, incineration or enzymatic hydrolysis. All these techniques are expensive, do not result in revalorisation or are not applicable at an industrial scale. In this paper, chemical hydrolysis is presented as an alternative to recover and increase the value of purified haemoglobin, the most abundant protein in blood. Non-enzymatic hydrolysis of haemoglobin is a good method for obtaining peptides due to its low cost, ease of control and the large amount of peptides produced, as well as being suitable for industrial applications. This paper presents a study of the use of two acids (sulfuric and hydrochloric) for this purpose under different experimental conditions. From the analysis of the kinetics of the hydrolysis process, four fractions can be defined: unbroken haemoglobin, soluble peptides, non-soluble peptides and free amino acids. A kinetic model was developed to simulate the hydrolysis mechanisms, providing a good fit to the experimental results. Both sulfuric and hydrochloric acid at concentrations of 6 M can hydrolyse the haemoglobin completely, but the average peptide size is lower for sulfuric than for hydrochloric acid.

Author(s):  
Mehdi Ashraf-Khorassani ◽  
William M. Coleman ◽  
Michael F. Dube ◽  
Larry T. Taylor

SummaryFree amino acids have been isolated via optimized enzymatic hydrolysis of F1 tobacco protein using two cationic resins (Amberlite IR120 and Dowex MAC-2). Optimized enzymatic conversions of the protein as a result of systematic variations in conditions (e.g., time, temperature, pH, enzyme type, enzyme concentration, anaerobic/aerobic environments, and protein concentration) employing commercially available enzymes, were consistently higher than 50% with qualitative amino acid arrays that were consistent with the known composition of tobacco F1 protein. Amberlite IR120 was shown to have a much higher efficiency and capacity for isolation of amino acids from standard solutions and from hydrolysate when compared with the results using Dowex MAC-2. Two columns packed with conditioned Amberlite IR120 (120 × 10 mm,12–15 g resin) and (200 × 25.4 mm, 60–65 g resin) were used to isolate two batches (2.5–3.0 mg and 13–15 mg) of free amino acids, respectively. A relatively inexpensive analytical methodology was developed for rapid analysis of the free amino acids contained within the enzyme hydrolysate. Commercially available enzymes, when employed in optimized reaction conditions, are very effective for enzymatic conversion of tobacco F1 protein to free amino acids.


2014 ◽  
Vol 70 (6) ◽  
pp. 1659-1668 ◽  
Author(s):  
Kwang-Hyun Park ◽  
Jong-Hyun Jung ◽  
Sung-Goo Park ◽  
Myeong-Eun Lee ◽  
James F. Holden ◽  
...  

A novel maltose-forming α-amylase (PSMA) was recently found in the hyperthermophilic archaeonPyrococcussp. ST04. This enzyme shows <13% amino-acid sequence identity to other known α-amylases and displays a unique enzymatic property in that it hydrolyzes both α-1,4-glucosidic and α-1,6-glucosidic linkages of substrates, recognizing only maltose units, in an exo-type manner. Here, the crystal structure of PSMA at a resolution of 1.8 Å is reported, showing a tight ring-shaped tetramer with monomers composed of two domains: an N-domain (amino acids 1–341) with a typical GH57 family (β/α)7-barrel fold and a C-domain (amino acids 342–597) composed of α-helical bundles. A small closed cavity observed in proximity to the catalytic residues Glu153 and Asp253 at the domain interface has the appropriate volume and geometry to bind a maltose unit, accounting for the selective exo-type maltose hydrolysis of the enzyme. A narrow gate at the putative subsite +1 formed by residue Phe218 and Phe452 is essential for specific cleavage of glucosidic bonds. The closed cavity at the active site is connected to a short substrate-binding channel that extends to the central hole of the tetramer, exhibiting a geometry that is significantly different from classical maltogenic amylases or β-amylases. The structural features of this novel exo-type maltose-forming α-amylase provide a molecular basis for its unique enzymatic characteristics and for its potential use in industrial applications and protein engineering.


1971 ◽  
Vol 24 (4) ◽  
pp. 1247 ◽  
Author(s):  
AS Inglis ◽  
PW Nicholls ◽  
CM Roxburgh

The phenylthiohydantoins (PTHs) derived from amino acids were hydrolysed in boiling hydriodic acid for 24 hr. Good yields of free amino acids were obtained for all PTH derivatives except methionine. In contrast to hydrolysis with hydrochloric acid, hydrolysis with hydriodic acid converts PTH-threonine, PTH-serine, and PTH-tryptophan respectively to oc-amino-n-butyric acid, alanine, and a mixture (approx. 2: 1) of glycine and alanine. This procedure provides a useful adjunct to thin-layer chromatography and ultraviolet spectroscopy for quantitative identification of the PTH derivative.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Yanbin Zheng ◽  
Qiushi Chen ◽  
Anshan Shan ◽  
Hao Zhang

For utilizing the blood cells (BCs) effectively, enzymatic hydrolysis was applied to produce the enzymatically hydrolyzed blood cells (EHBCs) by using a neutral protease as a catalyst. The results of the single-factor experiments showed optimal substrate concentration, enzyme to substrate ratio (E/S), pH, temperature, and incubation period were 1.00%, 0.10, 7.00, 50.00°C, and 12.00 h, respectively. The optimized hydrolysis conditions from response surface methodology (RSM) were pH 6.50, E/S 0.11, temperature 45.00°C, and incubation period 12.00 h. Under these conditions (substrate concentration 1.00%), the degree of hydrolysis (DH) was 35.06%. The free amino acids (FAAs) content of the EHBCs (35.24%) was 40.46 times higher than BCs while the total amino acids (TAAs) content was lower than BCs. The scores of lysine (human 0.87; pig 0.97), valine (human 1.42; pig 1.38), leucine (human 1.50; pig 1.90), tyrosine (human 0.84; pig 1.09), and histidine (human 2.17; pig 2.50) indicated that the EHBCs basically fulfilled the adult human and pig nutritional requirements. The calculated protein efficiency ratios (C-PERs) of the EHBCs were 3.94, 6.19, 21.73, and 2.04. In summary, the EHBCs were produced successfully with optimized conditions and could be a novel protein source for humans and pigs.


1952 ◽  
Vol 30 (8) ◽  
pp. 592-597 ◽  
Author(s):  
Paul E. Gagnon ◽  
Guy Nadeau ◽  
Raymond Côté

Monosubstituted cyanoacetic esters, obtained by condensation of 1-bromo-3(s)-phenoxypropanes (s = o-Cl, o-Br, o-I, o-, m-, and p-NO2) or 1-bromo-2(s)-phenoxyethanes (s = o-Cl, o-Br, o-I, and m-NO2) with ethyl cyanoacetate by means of potassium carbonate, were transformed through a Curtius degradation into cyanoacetisocyanates. These compounds by hydrolysis in acid or alkaline medium gave α-amino acids. However, hydrolysis of the corresponding carbobenzyloxy- or carbethoxyaminonitriles afforded better yields. The carbobenzyloxyaminonitriles were more readily hydrolyzed in aqueous hydrochloric acid than the carbethoxyaminonitriles. Moreover, the mild action of dry hydrochloric acid on the carbobenzyloxy derivatives yielded the α-amino acids readily whereas similar treatment of the carbethoxy derivatives gave the carbethoxyamino acids.


2012 ◽  
Vol 554-556 ◽  
pp. 1387-1394
Author(s):  
He Jian Xiong ◽  
Longfei Cao ◽  
Huajun You ◽  
Qingpi Yan ◽  
Ying Ma

Tilapia frames were subjected to enzymatic hydrolysis using Flavouzryme and Papain with a ratio of 2:1. The relationship of temperature (40 to 60°C), enzyme: substrate ratio (0.5% to 4.5%), initial pH (6.0 to 8.0) and hydrolysis time (1h to 9h) to the degree of hydrolysis were determined. The enzymatic hydrolysis was optimized for maximum degree of hydrolysis using surface response methodology. The optimum conditions for enzymatic hydrolysis of tilapia frames were temperature 53°C, enzyme : substrate ratio of 3.5%, initial pH 7.2, and reaction time 7h. Under these conditions a degree of hydrolysis of 40.01% were obtained. The yield of free amino acids in the hydrolysate was 46.61mg/g tilapia frames. The flavor amino acids and essential amino acids occupied up to 31.8% and 49.0% of the total free amino acids respectively. The hydrolysate of waste tilapia frames showed good potential for applications such as protein supplementation in food system.


1973 ◽  
Vol 51 (6) ◽  
pp. 1147-1153 ◽  
Author(s):  
James L. Harris ◽  
Willard A. Taber

The composition of the cell walls of synnemal and vegetative hyphae of Ceratocystis ulmi was studied by fractionation and assay of released compounds. Residues after enzymatic hydrolyses were examined by electron microscopy. The synnemal wall was found to have 67% carbohydrate, 4.52% amino sugar, 5.02% protein, 1.6% lipid, and 0.59% ash, which accounted for 78.7% of the cell wall. The vegetative hyphal wall contained 56% carbohydrate, 3.44% amino sugar, 7.92% protein, 4.5% lipid, and 1.45% ash, which totaled 73.3% of the wall weight. Sugars identified were D-glucose, D-mannose, D-galactose, and L-rhamnose. Enzymatic hydrolysis of both wall types by cellulase and laminaranase indicated the presence of beta-1,3 and beta-1,4 linkages of glucose polymers. N-acetylglucosamine was liberated by chitinase. Most of the 16 amino acids detected in each wall type were at least twice as abundant in vegetative hyphal walls as in synnemal hyphal walls. Cellulase and laminaranase treatment of cell walls revealed a fibrillar structure. Chitinase-treated walls did not appear as fibrous, suggesting that the fibrous structure may be mostly chitinous. Synnemal cell walls are covered by electron-dense granules which may correspond to the pigment in the synnemal hyphae.


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