Isolation and characterization of a peptide derived from the active site of chicken pepsin

1980 ◽  
Vol 45 (7) ◽  
pp. 2131-2134 ◽  
Author(s):  
Helena Keilová ◽  
Vladimír Kostka ◽  
Miroslav Baudyš
Keyword(s):  
Amino Acid ◽  
Methyl Ester ◽  
Amino Acid Composition ◽  
Aspartic Acid ◽  
Acid Composition ◽  
Active Site ◽  
Its Sequence ◽  
Aspartic Acid Residue ◽  
Isolation And Characterization

A peptide was isolated from chicken pepsin which contains the aspartic acid residue reacting with diazoacetyl-D,L-norleucine methyl ester in the presence of Cu2+ -ions. The peptide is N-terminated with isoleucine and contains (besides isoleucine) valine, aspartic acid, two threonines, serine, and leucine. In concurrent experiments a peptide of the same composition was isolated from the thermolysin digest of chicken pepsin and its sequence determined as Ile-Val-Asp-Thr-Gly-Thr-Ser-Leu. Since both peptides have entirely identical amino acid composition and other characteristics, the sequenced peptide corresponds to the peptide isolated from the active site of the enzyme.

Human pituitary thyrotropin. Isolation and characterization of the hormone and its subunits

1977 ◽  
Vol 55 (7) ◽  
pp. 747-754 ◽  
Author(s):  
M. R. Sairam ◽  
Choh Hao Li
Keyword(s):  
Biological Activity ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Disc Electrophoresis ◽  
Carbohydrate Content ◽  
Human Pituitary ◽  
Terminal Residue ◽  
Isolation And Characterization

Procedures have been described for the isolation of highly purified thyrotropin from frozen or acetone-preserved glands or from side fractions of somatotropin isolation and for the separation of its α and β subunits. The products have been characterized by terminal residue analyses, amino acid composition, carbohydrate content, disc electrophoresis, ultracentrifugation, and biological activity.

scholarly journals ISOLASI DAN KARAKTERISASI KOLAGEN DARI KULIT IKAN PATIN (Pangasius sp.)

2018 ◽  
Vol 8 (1) ◽  
pp. 8 ◽  
Author(s):  
Pipih Suptijah ◽  
Dini Indriani ◽  
Supriyono Eko Wardoyo
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Ph Value ◽  
Helical Structure ◽  
Color Analysis ◽  
Alternative Source ◽  
Isolation And Characterization ◽  
Naoh Solution

Isolation and Characterization of Collagen from the Skin of Catfish (Pangasius sp.)           Skin of catfish is one of aquatic by-products which could be used as an alternative source of collagen. This research is aimed to isolate and characterize collagen from skin of catfish. Methods of  isolation of collagen included three stages, the first was deproteinization using NaOH solution with concentration of 0.05 M; 0.10 M; 0.15 M; 0.20 M for 12 hours, the second was soaking in CH3COOH solution with concentration of 0.05 M; 0.10 M; 0.15 M; and 0.20 M for 2 hours, and the third was extraction in water at a temperature of 40 0C for 2 hours; characterization of collagen was included chemical and physical properties. The results showed that the best extraction method ofcollagen from skin of catfish was soaking the skin in 0.05 M NaOH solution for 12 hours and soaking the skin in 0.05 M acetic acid for 2 hours. Extraction yields of collagen was 12.15%. Chemical characteristics included proximate and amino acid composition. Proximate value of collagen consisted of moisture was 6.55%, ash 1.80%,  protein 64.74% and fat 8.85%.  The major amino acid composition of collagen were glycine, proline, alanine, arginine and glutamate. Physical characteristics of collagen resulted from FTIR analysis showed amide A, amide B, amide I, amide II and amide III, triple helical structure of the amide I and amide III indicates that the compound produced was collagen; color analysis was 66.39%; thermal analysis showed a melting temperature peak was 154.47 0C and pH value was 5.34.Keywords : Catfish, isolation, characterization, collagen, skin ABSTRAK          Kulit ikan patin merupakan salah satu limbah hasil perairan yang dapat digunakan sebagai sumber alternatif kolagen. Penelitian ini bertujuan untuk mengisolasi dan karakterisasi kolagen yang diperoleh dari kulit ikan patin. Isolasi kolagen yang dilakukan meliputi tiga tahap, yaitu tahap pertama adalah proses deproteinisasi menggunakan larutan NaOH dengan konsentrasi, yaitu 0,05 M; 0,10 M; 0,15 M; 0,20 M dan lama waktu perendaman selama 12 jam; tahap kedua, yaitu perendaman dalam larutan CH3COOH dengan empat konsentrasi CH3COOH yaitu 0,05 M; 0,10 M; 0,15 M; dan 0,20 M dan lama waktu perendaman selama 2 jam; dan tahap ketiga, yaitu ekstraksi dengan air pada suhu 40 0C selama 2 jam; serta karakterisasi kolagen yang dilakukan, meliputi sifat kimia dan fisik. Hasil penelitian menunjukkan bahwa metode ekstraksi kolagen dari kulit ikan patin  terbaik diperoleh melalui proses perendaman kulit dalam larutan NaOH 0,05 M selama 12 jam dan  perendaman kulit dalam asam asetat 0,05 M selama 2 jam.  Rendemen serbuk kolagen yang dihasilkan sebesar 12,15 %. Karakteristik kimia meliputi proksimat dan komposisi asam amino. Nilai proksimat kolagen terdiri dari kadar air 6,55 %,  abu 1,80 %, protein 64,74 % dan lemak 8,85 %. Komposisi asam amino yang dominan pada kolagen adalah glisina, prolina, alanina, arginina dan glutamat. Karakteristik fisik kolagen yang dihasilkan adalah analisis FTIR menunjukkan adanya gugus amida A, amida B, amida I, amida II dan amida III, struktur triple heliks pada amida I dan amida III mengindikasikan bahwa senyawa yang dihasilkan adalah kolagen; analisis warna  yaitu 66,39 %; analisis termal yang menunjukkan suhu puncak pelelehan adalah 154,47 0C dan nilai pH kolagen yaitu 5,34. Kata kunci : Ikan patin, isolasi, karakterisasi, kolagen, kulit 

scholarly journals The isolation and characterization of bovine C4a, an activation fragment of the fourth component of complement

1979 ◽  
Vol 183 (3) ◽  
pp. 573-578 ◽  
Author(s):  
N A Booth ◽  
R D Campbell ◽  
M A Smith ◽  
J E Fothergill
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Complement C4 ◽  
Alpha Chain ◽  
Isolation And Characterization ◽  
Fourth Component

The fourth component of bovine complement, C4, was cleaved specifically by subcomponent C1s to produce two fragments, C4a and C4b. The smaller, C4a, was isolated in pure form and is a peptide of 9500 mol.wt. containing approx. 84 amino acids and no detectable carbohydrate. C4a has an amino acid composition that is comparable with the anaphylatoxins C3a and C5a, containing six cysteine residues/mol and a high proportion of basic residues. The amino acid sequence of the first thirteen residues shows four identities with the porcine C3a sequence. There is almost complete identity between the C4a sequence and that of the alpha-chain of human C4, indicating that this region is highly conserved. This evidence also clearly establishes that C4a is cleaved from the N-terminal of the alpha-chain of C4.

scholarly journals Purification and Properties of Staphylocoagulase

1975 ◽  
Author(s):  
A.D. Muller ◽  
B. M. Bas ◽  
H. C. Hemker
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Aspartic Acid ◽  
Acid Composition ◽  
Isoelectric Point ◽  
Terminal Amino Acid ◽  
Purification And Properties ◽  
Terminal Amino

Staphylocoagulase, an exoprotein of coagulase positive staphylocoagulase, has been purified to a state in which only trace amounts of contaminating proteins are detectable.Purification was more than 35,000 fold, which is 7 times more than the highest value reported in the literature. The yield was about 15%.Aspartic acid was found as a single N-terminal amino acid in this preparation. The molecular weight is 61,000 and the isoelectric point lies at pH 4.53.The amino acid composition was determined.

scholarly journals An aspartic acid residue at the active site of pepsin. The isolation and sequence of the heptapeptide

1969 ◽  
Vol 113 (2) ◽  
pp. 377-386 ◽  
Author(s):  
R. S. Bayliss ◽  
J. R. Knowles ◽  
Grith B. Wybrandt
Keyword(s):  
Methyl Ester ◽  
Aspartic Acid ◽  
Active Site ◽  
Irreversible Inhibitor ◽  
Aspartic Acid Residue ◽  
Phenylalanine Methyl Ester

Pepsin reacts stoicheiometrically with the active-site-directed irreversible inhibitor N-diazoacetyl-l-phenylalanine methyl ester, with concomitant loss of all proteolytic and peptidolytic activity. The reagent esterifies a unique aspartic acid residue in pepsin, which is in the sequence:Ile-Val-Asp-Thr-Gly-Thr-Ser

scholarly journals An active-site peptide from pepsin C

1971 ◽  
Vol 123 (1) ◽  
pp. 75-82 ◽  
Author(s):  
J. Kay ◽  
A. P. Ryle
Keyword(s):  
Methyl Ester ◽  
Aspartic Acid ◽  
Active Site ◽  
Carboxyl Group ◽  
Active Site Residue ◽  
Aspartic Acid Residue ◽  
Porcine Pepsin ◽  
Ph Values ◽  
Complete Inactivation ◽  
Active Site Sequence

Porcine pepsin C is inactivated rapidly and irreversibly by diazoacetyl-dl-norleucine methyl ester in the presence of cupric ions at pH values above 4.5. The inactivation is specific in that complete inactivation accompanies the incorporation of 1mol of inhibitor residue/mol of enzyme and evidence has been obtained to suggest that the reaction occurs with an active site residue. The site of reaction is the β-carboxyl group of an aspartic acid residue in the sequence Ile-Val-Asp-Thr. This sequence is identical with the active-site sequence in pepsin and the significance of this in terms of the different activities of the two enzymes is discussed.

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