scholarly journals Isolation and characterization of sheep pepsin

1977 ◽  
Vol 161 (2) ◽  
pp. 389-398 ◽  
Author(s):  
P F Fox ◽  
J R Whitaker

Sheep pepsin was isolated (approx. 120-fold purification) from aqueous abomasal homogenates by (1) pH fractionation, (2) chromatography on Sepharose 4B-poly-L-lysine columns and (3) gel filtration on Sephadex G-100. The enzyme had mol.wt. approx. 34000, N-terminal valine and C-terminal alanine. The amino acid composition of sheep pepsin was generally similar to that of pig and ox pepsins, with a very low content of basic residues and a high content of acidic and hydroxy-amino acids. The pH optimum for NN-dimethyl-casein and NN-dimethyl-haemoglobin as substrates was approx. 1.8. The Km and kcat. for NN-dimethyl-haemoglobin were 46micronM and 1100min-1 respectively, and for NN-dimethyl-casein the corresponding parameters were 50micronM and 420min-1. These values were generally similar to those for pig and ox pepsins. At the pH optimum of 4.6, the sheep pepsin was about 50% as active on benzyloxycarbonyl-L-histidyl-L-phenyl-alanyl-L-tryptophan ethyl ester as was pig pepsin. The pH optimum for the hydrolysis of N-acetyl-L-phenylalanyl-L-di-iodotyrosine by sheep, ox and pig pepsins was approx. 1.85.

1979 ◽  
Vol 183 (3) ◽  
pp. 573-578 ◽  
Author(s):  
N A Booth ◽  
R D Campbell ◽  
M A Smith ◽  
J E Fothergill

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.


1974 ◽  
Vol 31 (01) ◽  
pp. 072-085 ◽  
Author(s):  
M Kopitar ◽  
M Stegnar ◽  
B Accetto ◽  
D Lebez

SummaryPlasminogen activator was isolated from disrupted pig leucocytes by the aid of DEAE chromatography, gel filtration on Sephadex G-100 and final purification on CM cellulose, or by preparative gel electrophoresis.Isolated plasminogen activator corresponds No. 3 band of the starting sample of leucocyte cells (that is composed from 10 gel electrophoretic bands).pH optimum was found to be in pH range 8.0–8.5 and the highest pH stability is between pH range 5.0–8.0.Inhibition studies of isolated plasminogen activator were performed with EACA, AMCHA, PAMBA and Trasylol, using Anson and Astrup method. By Astrup method 100% inhibition was found with EACA and Trasylol and 30% with AMCHA. PAMBA gave 60% inhibition already at concentration 10–3 M/ml. Molecular weight of plasminogen activator was determined by gel filtration on Sephadex G-100. The value obtained from 4 different samples was found to be 28000–30500.


1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.


1971 ◽  
Vol 124 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Abraham Spector ◽  
Lu-Ku Li ◽  
Robert C. Augusteyn ◽  
Arthur Schneider ◽  
Thomas Freund

α-Crystallin was isolated from calf lens periphery by chromatography on DEAE-cellulose and gel filtration. Three distinct populations of macromolecules have been isolated with molecular weights in the ranges approx. 6×105−9×105, 0.9×106−4×106and greater than 10×106. The concentration of macromolecules at the molecular-weight limits of a population are very low. The members of the different populations do not appear to be in equilibrium with each other. Further, in those molecular-weight fractions investigated, no equilibrium between members of the same population was observed. The population of lowest molecular weight comprises 65–75% of the total material. The amino acid and subunit composition of the different-sized fractions appear very similar, if not identical. The only chemical difference observed between the fractions is the presence of significant amounts of sugar in the higher-molecular-weight fractions. Subunit molecular weights of approx. 19.5×103and 22.5×103were observed for all α-crystallin fractions.


1956 ◽  
Vol 104 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Kenneth E. Lentz ◽  
Leonard T. Skeggs ◽  
Kenneth R. Woods ◽  
Joseph R. Kahn ◽  
Norman P. Shumway

Preparations of hypertensin II, obtained from the treatment of hypertensin I by the action of the hypertensin converting enzyme of plasma and purified by countercurrent distribution, were quantitatively analyzed for their amino acid content. Chromatography on ion exchange columns showed the presence of equimolar amounts of aspartic acid, proline, valine, isoleucine, tyrosine, phenylalanine, histidine, and arginine. Hypertensin I was found to contain one mole of leucine and one mole of histidine in addition to the amino acids of hypertensin II. These two amino acids were isolated from the conversion products of hypertensin I and identified as the peptide histidylleucine. Carboxypeptidase digestion of hypertensin I showed the carboxyl terminal sequence of amino acids to be residue-phenylalanyl-histidylleucine. Similar studies of hypertensin II demonstrated residue-phenylalanine. It was concluded that the conversion of hypertensin I by the plasma hypertensin converting enzyme involved hydrolysis of the phenylalanyl-histidine bond to form hypertensin II and histidylleucine. The further removal by carboxypeptidase of phenylalanine from hypertensin II destroyed all of the vasoconstrictor activity.


1976 ◽  
Vol 54 (10) ◽  
pp. 872-884 ◽  
Author(s):  
Alexander Kurosky ◽  
Theo Hofmann

The amino acid sequences of 48 peptides obtained from a chymotryptic digest of the mould acid protease, penicillopepsin (EC 3.4.23.7), have been determined. These peptides established the sequences of 26 unique fragments of up to 28 residues in length. The 28-residue fragment was identified as the N-terminal region. The C-terminal region is represented by a 13-residue fragment. The amino acids contained in these fragments account for some 85% of the residues of the enzyme.


2016 ◽  
Vol 77 (1) ◽  
Author(s):  
. TRI-PANJI ◽  
. SUHARYANTO ◽  
Marini WIJAYANTI

AbstractSpirulina platensis is a blue-green microalgawhich is frequently used for food and feedsupplements and cosmetic active agent. Thismicroalga also produces a strong antioxidantnamely superoxide dismutase (SOD) used ascosmetic active agent for anti aging and anti freeradicals. SOD was isolated from S. platensis cellbiomass from local isolate grown on latex serumon semipilot (3.5 m 3 ) and pilot scale (40 m 3 )then dried with spray drying or sun drying andcharacterized. SOD was purified with sequentialtwo-stage sedimentation using ammoniumsulphate and fractionated in chromatographiccolumn containing Sephadex G 200. Thefractions were analysed to determine the activity,cofactor metal and amino acid composition of theantioxidant. The results showed thatsedimentation of SOD extract with 80%ammonium sulphate produced SOD with higheractivity compared to that of SOD fromcommercial S. platensis biomass. This SOD wassuccessfully isolated and purified. MetaloenzymeSOD was composed of subunits with molecularweight of 77.78; 71.74; and 19.2 kDa, whichcontained nine types of amino acids with tyrosineand lysine as the major amino acid components.Zn was the most predominant metal on SOD, thenfollowed by Fe and Mn. The main subunitcofactors consisted of Zn 72%, Fe 25%, Mn 2%,and Cu 1%, which were different from thesmall subunit that contained of Zn 55%, Mn 31%,Fe 14%, and Cu 4%. The stability of SOD wasachieved on pH 7.5 and temperature below 25 o C.AbstrakSpirulina platensis adalah mikroalga hijaubiru yang banyak digunakan sebagai suplemenpangan, pakan, dan bahan aktif kosmetika.Mikroalga ini juga menghasilkan antioksidankuat yaitu superoksida dismutase (SOD), yangmerupakan bahan aktif kosmetika anti penuaandini dan pencegah efek radikal bebas. SODdiisolasi dari biomassa sel S. platensis isolat lokalyang dibiakkan dalam serum lateks skalasemipilot (3,5 m 3 ) dan pilot (40 m 3 ) sertadikeringkan dengan cara pengeringan kabut(spray drying) atau penjemuran untuk kemudiandikarakterisasi. SOD dimurnikan dengan peng-endapan bertingkat menggunakan ammoniumsulfat dan dipisahkan dengan kolom kromatografiberisi Sephadex G 200. Hasil pemisahankemudian dianalisis untuk menentukan aktivitas,logam kofaktor serta komposisi asam amino antioksidan tersebut. Hasil penelitian menunjukkanbahwa pengendapan ekstrak SOD denganSOD lebih tinggi dari SOD asal biomassaS. platensis komersial. SOD tersebut telahberhasil diisolasi dan dimurnikan. MetaloenzimSOD tersusun atas subunit dengan BM 77,78;71,74; dan 19,2 kDa, yang mengandungsembilan jenis asam amino dengan tirosin danlisin sebagai komponen asam amino utama.Logam yang dominan pada SOD adalah Zn,disusul kemudian Fe dan Mn. Kofaktor sub unitbesar terdiri dari Zn 72%, Fe 25%, Mn 2%, danCu 1%, berbeda dengan sub unit kecil yangmengandung Zn 55%, Mn 31%, Fe 14%, dan Cu4%. Stabilitas SOD S. platensis dicapai pada pH7,5 dan suhu di bawah 25 o Cammonium sulfat 80% menghasilkan aktivitas


1970 ◽  
Vol 48 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
C. Gilardeau ◽  
M. Chrétien

A lipolytic substance was isolated from porcine pituitary glands. It's amino acid composition, molecular weight, N-terminal amino acid, isoelectric point, and biological activities are reported. These results are compared to the corresponding values of sheep β-lipolytic hormone.


1971 ◽  
Vol 123 (5) ◽  
pp. 845-853 ◽  
Author(s):  
D. Snary ◽  
A. Allen

1. Gel filtration of the water-soluble radioactive mucus produced three radioactive fractions, fraction A excluded on Sepharose 4B, fraction B included on Sepharose 4B but excluded on Sephadex G-200, and fraction C included on Sephadex G-200. 2. The specific radioactivities of fractions A and B were the same, with fraction C a little lower, whether the material was labelled with 14C-labelled carbohydrate or with 3H-labelled protein prepared by incubation of mucosal scrapings in vitro with [U-14C]glucose or [G-3H]threonine respectively. 3. Fractions A and B had an analysis of protein 22%, hexose 28%, hexosamine 28%, fucose 10% and sialic acid 1%; fraction C had an analysis closely similar to this, except that it contained about 10% of a protein contaminant. 4. All three fractions had closely similar A and H blood-group activities. 5. Ultracentrifuge studies showed fractions A, B and C were polydisperse with s025,w values of 18.7S, 4.9S and 3.9S respectively. 6. The unfractionated water-soluble mucus contained only two peaks, fraction A 18.7S and a peak of 4.4S, which was a combination of fractions B and C. 7. The radioactive mucoprotein accounted for 85% by weight of the soluble mucus and the results show that it consisted of two distinct fractions A and B–C, which were chemically, biosynthetically and immunologically very similar.


1996 ◽  
Vol 316 (3) ◽  
pp. 841-846 ◽  
Author(s):  
Stuart M. PITSON ◽  
Robert J. SEVIOUR ◽  
Barbara M. McDOUGALL ◽  
Bruce A. STONE ◽  
Maruse SADEK

An endo-(1 → 6)-β-glucanase has been isolated from the culture filtrates of the filamentous fungus Acremonium persicinum and purified by (NH4)2SO4 precipitation followed by anion-exchange and gel-filtration chromatography. SDS/PAGE of the purified enzyme gave a single band with an apparent molecular mass of 42.7 kDa. The enzyme is a non-glycosylated, monomeric protein with a pI of 4.9 and pH optimum of 5.0. It hydrolysed (1 → 6)-β-glucans (pustulan and lutean), initially yielding a series of (1 → 6)-β-linked oligoglucosides, consistent with endo-hydrolytic action. Final hydrolysis products from these substrates were gentiobiose and gentiotriose, with all products released as β-anomers, indicating that the enzyme acts with retention of configuration. The purified enzyme also hydrolysed Eisenia bicyclis laminarin, liberating glucose, gentiobiose, and a range of larger oligoglucosides, through the apparent hydrolysis of (1 → 6)-β- and some (1 → 3)-β-linkages in this substrate. Km values for pustulan, lutean and laminarin were 1.28, 1.38, and 1.67 mg/ml respectively. The enzyme was inhibited by N-acetylimidazole, N-bromosuccinimide, dicyclohexylcarbodi-imide, Woodward's Regent K, 2-hydroxy-5-nitrobenzyl bromide, KMnO4 and some metal ions, whereas D-glucono-1,5-lactone and EDTA had no effect.


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