The Amino Acid Composition of Crystalline Pepsin

Blumenfeld, Olga O.; Perlmann, Gertrude E.

doi:10.1085/jgp.42.3.553

Cited by 57 publications

(8 citation statements)

References 16 publications

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“…Moreover, the obtained results are also similar with the ones obtained with other elasmobranch species [10]. In turn, the major amino acids present in ray PSC extract were glycine, serine, and aspartic acid, which may be explained by the inefficient removal of pepsin used in the enzymatic treatment that had a high composition of aspartic acid and serine [63], confirming the impurity of this extract as suggested earlier by UV spectroscopic analysis.…”

Section: Amino Acid Analysissupporting

confidence: 88%

Extraction and Characterization of Collagen from Elasmobranch Byproducts for Potential Biomaterial Use

et al. 2020

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With the worldwide increase of fisheries, fish wastes have had a similar increase, alternatively they can be seen as a source of novel substances for the improvement of society’s wellbeing. Elasmobranchs are a subclass fished in high amounts, with some species being mainly bycatch. They possess an endoskeleton composed mainly by cartilage, from which chondroitin sulfate is currently obtained. Their use as a viable source for extraction of type II collagen has been hypothesized with the envisaging of a biomedical application, namely in biomaterials production. In the present work, raw cartilage from shark (Prionace glauca) and ray (Zeachara chilensis and Bathyraja brachyurops) was obtained from a fish processing company and submitted to acidic and enzymatic extractions, to produce acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC). From all the extractions, P. glauca PSC had the highest yield (3.5%), followed by ray ASC (0.92%), ray PSC (0.50%), and P. glauca ASC (0.15%). All the extracts showed similar properties, with the SDS-PAGE profiles being compatible with the presence of both type I and type II collagens. Moreover, the collagen extracts exhibited the competence to maintain their conformation at human basal temperature, presenting a denaturation temperature higher than 37 °C. Hydrogels were produced using P. glauca PSC combined with shark chondroitin sulfate, with the objective of mimicking the human cartilage extracellular matrix. These hydrogels were cohesive and structurally-stable at 37 °C, with rheological measurements exhibiting a conformation of an elastic solid when submitted to shear strain with a frequency up to 4 Hz. This work revealed a sustainable strategy for the valorization of fisheries’ by-products, within the concept of a circular economy, consisting of the use of P. glauca, Z. chilensis, and B. brachyurops cartilage for the extraction of collagen, which would be further employed in the development of hydrogels as a proof of concept of its biotechnological potential, ultimately envisaging its use in marine biomaterials to regenerate damaged cartilaginous tissues.

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Section: Amino Acid Analysissupporting

confidence: 88%

Extraction and Characterization of Collagen from Elasmobranch Byproducts for Potential Biomaterial Use

et al. 2020

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“…If these changes are represented as difference spectra three peaks with maxima at 2770, 2850, and 2940 /~ are present which can be attributed to the presence of tyrosine and tryptophan in the protein. In view of the fact that the pepsin preparation used in this research contains 18 tyrosines, 6 tryptophans, 71 dicarboxylic acids with 36 amides, aI~d 35 free carboxyl groups (17), hydrogen bonds of the type sug-gested by Scheraga and coworkers could exist between the phenolic hydroxyls of tyrosine and the imino group of tryptophan on one hand and a basic group; i.e., carboxylate on the other.…”

Section: Discussionmentioning

confidence: 99%

Ultraviolet Difference Spectra of Pepsin

Blumenfeld

Perlmann

1959

The Journal of General Physiology

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A shift of pH of pepsin solutions from 4.6 to 1.0 gives rise to spectral displacemerits in the ultraviolet. If represented as difference spectra three peaks with maxima at 2770, 2850, and 2930 ,~mgstr~ms are present which can be attributed to the tyrosine and tryptophan residues in the protein. On mild autolysis of pepsin at pH 2.0 the absorbancy in the ultraviolet further decreases. Although some of these effects can be ascribed to the occurrence of hydrogen bonding between the aromatic residues and a carboxylate ion, those observed on autolysis are caused by charge effects of newly formed polar groups in the vicinity of a chromophore. No direct relation between the optical properties described here and enzymic activity of pepsin has been observed.The ultraviolet absorption bands of protein solutions are displaced to shorter wave lengths on titration of a protein with acid (1), upon denaturation with urea or guanidine salts (2-4), and on mild proteolysis (2, 3, 5, 6). Recently, Laskowski, Scheraga, and coworkers have studied the spectral shifts that occur if the pH of solutions of insulin and ribonuclease is altered from neutrality to pH 1.0 (6, 7). On the basis of their results these investigators proposed the hypothesis, at present widely accepted, that these small spectral displacements reflect changes in the hydrogen bonding between the tyrosyl hydroxyls and neighboring basic groups of the protein; e.g., carboxylates.An alternative explanation, however, follows from the work of Wetlaufer, Edsall, and Hollingworth, who observed spectral changes of the same order of magnitude if solutions of tyrosine, O-methyltyrosine, and glycyl O-methyltyrosine of pH 7.0 are compared with those of pH 1.0 (8). Since the occurrence, in these materials, of intramolecular hydrogen bonds can be excluded these

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“…The amino acid profiles of pepsin (Blumenfeld and Perlmann, 1958;Tang et al, 1973) and mucin (Lien et al, 1997) may be compared with the amino acid composition of the basal diet and the quantities of ileal digestible amino acids generated by phytase in broilers . The amino acid profile of pepsin was not correlated to dietary amino acids (r = 0.32; P N 0.05) but it was significantly correlated to the amino acids generated by phytase (r = 0.61; P b 0.01).…”

Section: Underlying Mechanismsmentioning

confidence: 99%