Isolation of specific protease inhibitors from Neurospora crassa

1976 ◽  
Vol 54 (8) ◽  
pp. 699-703 ◽  
Author(s):  
Peter H. Yu ◽  
Maria R. Kula ◽  
Hsin Tsai

Four natural protease inhibitors have been partially purified by heat treatment, ion-exchange chromatography and gel filtration from Neurospora crassa. The inhibitory activity has been estimated by measuring the inhibition of proteolysis of casein as well as by the protection of Neurospora tryptophan synthase from proteolytic inactivation. The inhibitors are all oligopeptides and possess molecular weights in the range 5000 – 24 000 and appear to be very specific to Neurospora proteases. They may be classified into two types. The first are specific to Neurospora alkaline protease and the second to acidic protease. None of them exhibited any effect on other proteases including trypsin, chymotrypsin, papain, pepsin, thermolysin, subtilisin and proteinase K. The possible physiological role of these inhibitors is discussed.

1970 ◽  
Vol 48 (4) ◽  
pp. 455-462 ◽  
Author(s):  
Seon Shin ◽  
Frank LaBella ◽  
Gary Queen

A number of peptides and amino acids, representing 30–40% of the total acid-extractable, ninhydrin-positive material of the tissue, were associated with cytoplasmic granules (sedimenting at 3 000 000 g-min after preliminary removal of "nuclei and debris") isolated from bovine posterior pituitary glands. Acetic acid (0.2 N) extracts of a purified neurosecretory granule fraction showed only slight differences in the pattern of peptides and amino acids from extracts of the total cell particulate fraction. Gel filtration of extracts on Sephadex G-25 yielded three major fractions: fraction I consisting of peptide material of molecular weights > 4000, fraction II of molecular weights averaging about 3000, and fraction III of molecular weights < 2000. Fraction III was further resolved by anion-exchange chromatography into 12 subfractions. Vasopressin and oxytocin were contained in subfractions 2 and 3, respectively. Each of these subfractions was in turn chromatographed on a cation-exchange resin and resolved into a total for fraction III of 22 major components: lysine, arginine, phenylalanine, ammonia, and 18 peptides. Three of the peptides contained only aspartic and glutamic acids in the ratios 8:1, 5:1, and 4:1. The sequences of four dipeptides were ascertained. Another peptide was not retarded by Dowex 50 and yielded glutamic acid upon acid hydrolysis. Still another peptide yielded tyrosine plus an unknown ninhydrin-positive component after hydrolysis. The amino acid compositions were determined for nine other peptides containing three to nine residues. Additional peptides in fraction III were detected in lesser or trace amounts. Isolated granule fractions from both bovine posterior pituitary and rat liver were dialyzed against isotonic sucrose or distilled water. The rate of loss of ninhydrin-positive material from the sample dialyzed against water indicated that a large proportion of the "free" amino acids and peptides of these tissues were contained within intracellular organelles.


2016 ◽  
Vol 78 (6-5) ◽  
Author(s):  
Zainon Mohd Noor ◽  
Mohd Sidek Ahmad ◽  
Zaidah Zainal Ariffin

Three enzymes FH3, S13 and LR1 from three different sources showed fibrinolytic activities. Two were from endophytic fungal cultures and one from the sclerotium of Lignosus rhinocerus mushroom (LR1). FH3, S13 cultures and LR1, the crude extract of the sclerotium were concentrated and purified by ammonium sulphate precipitation, ion-exchange chromatography and gel-filtration. The molecular weights of the FH3, S13 and LR1 purified enzymes were estimated to be approximately 34kDa, 34kDa and 10kDa, respectively. Maximum fibrinolytic activities were observed for FH3 at pH 7 and 30°C, S13 at pH 8 and 40°C and LR1 at pH 6 and 40°C.  In our earlier paper we identified FH3 as Fusarium sp. and S13 as Penicilium citrinum. 


1987 ◽  
Vol 65 (10) ◽  
pp. 899-908 ◽  
Author(s):  
F. Moranelli ◽  
M. Yaguchi ◽  
G. B. Calleja ◽  
A. Nasim

The extracellular α-amylase activity of the yeast Schwanniomyces alluvius has been purified by anion-exchange chromatography on DEAE-cellulose and gel-filtration chromatography on Sephadex G-100. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) and N-terminal amino acid analysis of the purified sample indicated that the enzyme preparation was homogeneous. The enzyme is a glycoprotein having a molecular mass of 52 kilodaltons (kDa) estimated by SDS–PAGE and 39 kDa by gel filtration on Sephadex G-100. Chromatofocusing shows that it is an acidic protein. It is resistant to trypsin but sensitive to proteinase K. Its activity is inhibited by the divalent cation chelators EDTA and EGTA and it is insensitive to sulfhydryl-blocking agents. Exogenous divalent cations are inhibitory as are high concentrations of monovalent salts. The enzyme has a pH optimum between 3.75 and 5.5 and displays maximum stability in the pH range of 4.0–7.0. Under the conditions tested, the activity is maximal between 45 and 50 °C and is very thermolabile. Analysis of its amino acid composition supports its acidic nature.


1974 ◽  
Vol 141 (2) ◽  
pp. 427-437 ◽  
Author(s):  
Philip J. Lowry ◽  
Hugh P. J. Bennett ◽  
Colin McMartin ◽  
Alexander P. Scott

An adrenocorticotrophic hormone (ACTH) was isolated from extracts of the pars distalis of the pituitary of the dogfish Squalus acanthias by gel filtration and ion-exchange chromatography. It had 15% of the potency of human ACTH in promoting cortico-steroidogenesis in isolated rat adrenal cells. Sequence analysis revealed it to be a nonatria-contapeptide with the following primary structure: Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Lys-Pro-Met-Gly-Arg-Lys-Arg-Arg-Pro-Ile-Lys-Val-Tyr-Pro-Asn-Ser-Phe-Glu-Asp-Glu-Ser-Val-Glu-Asn-Met-Gly-Pro-Glu-Leu. The N-terminal tridecapeptide sequence was identical with the proposed structure of dogfish α-melanocyte-stimulating hormone (α-MSH). On comparison with human ACTH eleven amino acid differences were seen, nine of which are in the 20–39 region of the molecule which is not essential for the steroidogenic activity of ACTH. A peptide identical with the 18–39 portion of this new ACTH was similarly isolated from the neurointermediate lobe of the pituitary where considerable amounts of dogfish α-MSH were found. This supported our view that ACTH as well as having a distinct biological role of its own is also the precursor of α-MSH.


1974 ◽  
Vol 77 (3) ◽  
pp. 485-497 ◽  
Author(s):  
P. A. Torjesen ◽  
T. Sand ◽  
N. Norman ◽  
O. Trygstad ◽  
I. Foss

ABSTRACT Highly purified human LH, FSH and TSH were isolated from batches of 300 frozen pituitary glands (200 g) by pH, acetone and ethanol fractionation, Sephadex gel filtration, ion-exchange chromatography on DEAE-cellulose and CM-Sephadex, and preparative polyacrylamide-gel electrophoresis. Sodium dodecyl-sulphate (SDS) polyacrylamide gel electrophoresis was used in order to check the purity, the identity and the molecular weight of the purified LH, FSH and TSH. This procedure showed that the hormone preparations consisted of two subunits with molecular weights of: LH: 21 300 and 17 900, FSH: 22 100 and 18 300 and TSH: 20 800 and 16 400. The purity of the hormone preparations was also evaluated by analytical disc electrophoresis at pH 8.9. The purified hormone preparations had radioimmunological activity as follows: LH: 20 000 IU/mg, FSH: 16 500 IU/mg and TSH: 5 IU/mg. All preparations had high biological potency.


Microbiology ◽  
2003 ◽  
Vol 149 (10) ◽  
pp. 2919-2929 ◽  
Author(s):  
Declan C. Schroeder ◽  
Mohamed A. Jaffer ◽  
Vernon E. Coyne

Gracilaria species are an important source of agar. The South African Gracilaria industry has experienced a number of setbacks over the last decade in the form of complete or partial die-offs of the agarophyte growing in Saldanha Bay, which may be attributed to bacterial infection. Since a positive correlation was observed between the presence of agarolytic epiphytes and bacterial pathogenicity, we investigated the role of an agarase in the virulence mechanism employed by a bacterium that elicits disease in Gracilaria gracilis. The recombinant plasmid pDA1, isolated from a Pseudoalteromonas gracilis B9 genomic library, was responsible for the agarolytic activity exhibited by Escherichia coli transformants when grown on solid medium. A blast search of the GenBank database showed that an 873 bp ORF (aagA) located on pDA1 had 85 % identity to the β-agarase (dagA) from Pseudoalteromonas atlantica ATCC 19262T (or IAM 12927T) at the amino acid level. AagA was purified from the extracellular medium of an E. coli transformant harbouring pDA1 by using a combination of gel filtration and ion-exchange chromatography. AagA has an M r of 30 000 on SDS-PAGE. TLC of the digestion products of AagA showed that the enzyme cleaves the β-(1,4) linkages of agarose to yield predominately neoagarotetraose. Western hybridization confirmed that the cloned agarase was in fact the extracellular β-agarase of P. gracilis B9. The observed relationship between disease symptoms of G. gracilis and the agarolytic phenotype of P. gracilis B9 was confirmed. Transmission electron microscope examination of cross sections of both healthy G. gracilis and G. gracilis infected with P. gracilis, revealed a weakening of the cell structure in the latter plants. Immunogold-labelled antibodies localized the agarase in situ to the cell walls of bleached G. gracilis. Thus, the weakening observed in the cell structure of G. gracilis infected with P. gracilis can be attributed to degradation of the mucilaginous component of the cell wall of the bleached thalli.


1981 ◽  
Vol 59 (11) ◽  
pp. 2186-2192 ◽  
Author(s):  
Choy L. Hew ◽  
Don Slaughter ◽  
Garth L. Fletcher ◽  
Shashikant B. Joshi

The plasma of the Atlantic cod, Gadus morhua, contained antifreeze glycoproteins which were present only during the winter months. The antifreeze proteins were isolated, using gel filtration and ion exchange chromatography, and characterized by high performance liquid chromatography. The antifreeze proteins appeared to consist of at least seven components with molecular weights ranging from 2 500 to 33 000. Chemical analysis of the larger components showed a predominance of alanine, threonine, and galactosamine in a ratio of 2:1:1. The smaller peptides contained proline, in addition to alanine and threonine. The amino acid sequence of the smallest glycopeptide (molecular weight 2500) was found to be Ala Ala Thr Pro Ala Thr Ala Ala Thr Pro Ala Thr Ala Ala.These glycoproteins are very similar, if not identical, in amino acid and carbohydrate composition to those isolated from Antaractic nototheniids and several northern gadoids. The sequence of the smallest glycopeptide from the Atlantic cod is identical to that reported for the polar cod, Boreogadus saida.


1983 ◽  
Vol 215 (2) ◽  
pp. 325-334 ◽  
Author(s):  
M G Low ◽  
W B Weglicki

Phospholipase C activity capable of hydrolysing phosphatidylinositol in bovine heart was resolved into four forms (I-IV) by ion-exchange chromatography. Some of these forms could only be detected if the assay was performed at acidic pH (I and IV) or in the presence of deoxycholate (II). Gel-filtration chromatography indicated that the four forms had different molecular weights in the range 40000-120000. I, II and III all had pH optima in the range 4.5-5.5. However, the major form (III) also had substantial activity at pH 7.0 and above. The activities of I, II and III at pH 7.0 were stimulated by deoxycholate; this effect was most marked with I and II, which had very low activity at this pH. All forms of the enzyme were inhibited by EGTA and required 2-5 mM-CaCl2 for maximal activity. When the fractions eluted from the ion-exchange and gel-filtration columns were assayed with polyphosphoinositides as substrates there was a close correspondence to the elution profile obtained with phosphatidylinositol as substrate; there was no evidence for the existence in heart of phospholipase C activities specific for individual phosphoinositides.


Author(s):  
P.J. Glynn ◽  
A.L. Pulsford

Whole flounder serum has been fractionated by gel filtration on Ultrogel AcA22. Pooled material from the first major peak of the elution profile was further fractionated by FPLC ion-exchange chromatography and this yielded one major and three minor peaks. Under both reducing and non-reducing conditions SDS electrophoresis showed that the major peak and two of the minor ones were immunoglobulin (Ig). All three of these Ig populations were tetrameric, with estimated molecular weights of 710 kD. However, approximately 90% of the major Ig species consisted of tetramers which were covalently linked by disulphide bonds, whereas the remaining 10% was composed of dimeric molecules held together by non-covalent interactions. The heavy chains of all three Ig populations had apparent molecular weights of approximately 72 kD but the light chain composition showed considerable heterogeneity. In the major population, five polypep-tides were detected in the light chain region of the gel with apparent molecular weights covering the range 22–28 kD. However, there was no difference in the light chain composition of covalently and non-covalently linked tetramers. The two minor populations differed both from each other and from the major species in respect of their light chain compositions. No evidence was found for a monomeric serum Ig, and alkaline urea electrophoresis failed to demonstrate a J chain.


2013 ◽  
Vol 53 (4) ◽  
pp. 324-332 ◽  
Author(s):  
Tahareh Gholami ◽  
Mohammad Ghadamyari ◽  
Ali Olyaie Oliaee ◽  
Maryan Ajamhasani

Abstract The rosaceous branch borer, Ospheranteria coerulescens, is an important pest of rosaceous trees. This insect feeds on the twigs and branches of living trees and causes their death. The characterization of the insect phenoloxidase (PO) is of interest when doing comparative investigations, and so that we may be able to understand its biochemical properties. When designing new methods of insect control such as the use of PO inhibitors, an understanding of the biochemical properties is fundamental. In this study, PO from hemolymph of the rosaceous branch borer was purified using ammonium sulfate precipitation, gel-filtration, and ion-exchange chromatography. The biochemical properties were characterized using l-dihydroxyphenylalanine (L-DOPA) as the specific substrate. The apparent molecular weights of the three isoforms of PO were determined by SDS-PAGE to be 85.23, 79.45, and 66.06 kDa. Optimal pH for PO activity was pH 8, and the optimal temperature was 45°C. Phenoloxidase lost less than 50% of its relative activity after a 60 min incubation at the optimal temperature. The effects of ions and chemical materials such as K+, Ba2+, Zn2+ and EDTA on PO showed that PO activity was strongly inhibited by Zn2+. The Michaelis constant (Km) and maximum velocity (Vmax) were 88.61 mM and 0.14 μmol/min, respectively. The inhibitory effects of kojic acid, 4-hexylresorsinol, and quercetin on PO were determined, and the IC50s (inhibitory concentration) were estimated as 23.31 for kojic acid, 35.75 for 4-hexylresorcinol, and 60.8 μM for quercetin. The inhibitory potency of kojic acid was 1.54 times higher than that of 4-hexylresorcinol and 2.58 times higher than that of quercetin. Phenoloxidase was effectively inhibited by 4-hexylresorcinol, and the inhibition type was competitive. The inhibition types of PO by kojic acid and quercetin were found to be mixed.


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