A Bacteriocin Produced by Lactobacillus brevis KLDS1.0373 Isolated from “Jiaoke”, a Traditional Fermented Cream from China

2011 ◽  
Vol 183-185 ◽  
pp. 1132-1136
Author(s):  
Hui Wang ◽  
Han Sheng Gong ◽  
Xiang Chen Meng ◽  
Li Li Man

A bacteriocin produced by Lactobacillus brevis KLDS1.0373 which was isolated from “Jiaoke”, a traditional, naturally fermented cream from Inner Mongolia in China was reported in this article. The bacteriocin was partially purified by ammonium sulfate precipitation followed by sequential gel filtration chromatography, and the apparent molecular weight of the partially purified bacteriocin was estimated at approximately 3.8 kDa.

1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)


2013 ◽  
Vol 10 (2) ◽  
pp. 29
Author(s):  
Normah Ismail ◽  
Nur' Ain Mohamad Kharoe

Unripe and ripe bilimbi (Averrhoa bilimbi L.) were ground and the extracted juices were partially purified by ammonium sulfate precipitation at the concentrations of 40 and 60% (w/v). The collected proteases were analysed for pH, temperature stability, storage stability, molecular weight distribution, protein concentration and protein content. Protein content of bilimbi fruit was 0.89 g. Protease activity of both the unripe and ripe fruit were optimum at pH 4 and 40°C when the juice were purified at 40 and 60% ammonium sulfate precipitation. A decreased in protease activity was observed during the seven days of storage at 4°C. Molecular weight distribution indicated that the proteases protein bands fall between IO to 220 kDa. Protein bands were observed at 25, 50 and 160 kDa in both the unripe and ripe bilimbi proteases purified with 40% ammonium sulfate, however, the bands were more intense in those from unripe bilimbi. No protein bands were seen in proteases purified with 60% ammonium sulfate. Protein concentration was higher for proteases extracted with 40% ammonium sulfate at both ripening stages. Thus, purification using 40% ammonium sulfate precipitation could be a successful method to partially purify proteases from bilimbi especially from the unripe stage. 


1976 ◽  
Vol 54 (2) ◽  
pp. 120-129 ◽  
Author(s):  
W. S. Rickert ◽  
P. A. McBride-Warren

The reaction of Mucor miehei protease with concanavalin A was followed by a turbidimetric assay in the pH range 5–8. At pH 4.0, no turbidity developed but binding of the enzyme to concanavalin A could be demonstrated by gel filtration. Two fractions of apparent molecular weight 65 000 and 52 000 were isolated, the 65 000 molecular weight species apparently representing a protomer of concanavalin A (24 000) bound to the enzyme. An analysis of the circular dichroism spectrum of this complex suggested that protomer binding results in a conformational change in the enzyme which is associated with a 30% increase in proteolytic activity.At pH 6.0, the enzyme was strongly bound to columns of concanavalin A Sepharose but could be removed by including α-methyl D-glucoside and NaCl in the elution buffer. Some column degradation occurred at room temperature but was not detectable at 4 °C where rapid elution of the enzyme resulted in a greater than 90% yield of highly active protein. Periodate-oxidized Mucor miehei protease and Mucor rennin did not react with concanavalin A and were not bound to the affinity column.


1976 ◽  
Vol 156 (1) ◽  
pp. 143-150 ◽  
Author(s):  
R H Quarles

Rats (14 days old) were injected with [14c]fucose and young adult rats with [3H]fucose in order to label the myelin-associated glycoproteins. As previously reported, the major [14C]fucose-labelled glycoprotein in the immature myelin had a higher apparent molecular weight on sodium dodecyl sulphate/polyacrylamide gels that the [3H]fucose-labelled glycoprotein in mature myelin. This predominant doubly labelled glycoprotein component was partially purified by preparative gel electrophoresis and converted to glycopeptides by extensive Pronase digestion. Gel filtration on Sephadex G-50 separated the glycopeptides into several clases, which were designted A,B, C AND D, from high to low molecular weight. The 14C-labelled glycopeptides from immature myeline were enriched in the highest-molecular-weight class A relative to the 3H-labelled glycopeptides from mature myelin. Neuraminidase treatment of the glycoprotein before Pronase digestion greatly decreased the proportion of glycopeptides fractionating in the higher-molecular-weight classes and largely eliminated the developmental differences that were apparent by gel filtration. However, neuraminidase treatment did not decrease the magnitude of the developmental difference revealed by electrophoresing the intact glycoprotein on sodium dodecyl sulphate gels, although it did decrease the apparent molecular weight of the glycoprotein from both the 15-day-old and adult rats by an amount comparable in magnitude to that developmental difference. The results from gel filtration of glycopeptides indicate that there is a higher content of large molecular weight, sialic acid-rich oligosaccharide units in the glycoprotein of immature myelin. However, the higher apparent molecular weight for the glycoprotein from 15-day-old rats on sodium dodcyl sulphate gels is not due primarily to its higher sialic acid content.


1980 ◽  
Vol 58 (5) ◽  
pp. 384-393 ◽  
Author(s):  
Maija-Liisa Rasilo ◽  
Jorma Wartiovaara ◽  
Ossi Renkonen

Human teratocarcinoma derived cells, line PA 1, maintained in the undifferentiated state, yielded upon exhaustive pronase digestion unusually large glycopeptides (fraction A), which showed on gel filtration an apparent molecular weight larger than 7400. These glycopeptides derived from whole cell proteins carried large-sized oligosaccharides as evidenced by repeated pronase treatments, hydrazinolysis, and β-elimination experiments. The oligosaccharides consisted of mannose, fucose, galactose, and N-acetylglucosamine.The PA 1 cells contained also oligomannosyl type glycans, presumably linked to asparagine (fraction C glycopeptides). These glycopeptides were strongly bound to Con A – Sepharose and their oligosaccharides were released by endo-β-N-acetylglucosaminidase H. The liberated glycans ranged from Man5GlcNAc to Man9GlcNAc as analyzed by paper chromatography."Pulse–chase" experiments suggest that there is a precursor–product relationship between the mannose label in the fraction C (oligomannosyl type) glycopeptides and the fraction A glycopeptides.


2003 ◽  
Vol 58 (11-12) ◽  
pp. 891-894 ◽  
Author(s):  
Teruhiko Nitoda ◽  
Hirokazu Usuki ◽  
Hiroshi Kanzaki

Abstract A water-soluble polysaccharide was isolated from the culture filtrate of a fungal strain, Sphaeropsis sp. TNPT116-Cz, as a novel insect chitinase inhibitor. It was purified to chromatographic homogeneity by ethanol precipitation, anion-exchange and gel filtration chromatography. Its molecular weight was estimated to be 16 kDa by gel filtration HPLC. Monosaccharide analysis showed that it contained glucose, galactose, N-acetylglucosamine and a deoxysugar. This polysaccharide showed potent and specific inhibitory activity against Spodoptera litura chitinase with an IC50 value of 28 nᴍ.


1969 ◽  
Vol 47 (11) ◽  
pp. 1021-1025 ◽  
Author(s):  
J. A. Blakely ◽  
S. L. MacKenzie

A β-hexosidase has been isolated from Sporobolomyces singularis by conventional techniques involving ammonium sulfate precipitation and chromatography on columns of Sephadex G-200 and DEAE-Sephadex A-50. Electrophoresis on polyacrylamide gel was used as the final preparative step. The sedimentation coefficient (s°20,w) of the enzyme was 7.6 and its molecular weight was in the range 140 000–145 000. Although the β-hexosidase performed the functions of a β-D-galactoside galactohydrolase (β-galactosidase), it also catalyzed the hydrolytic function normally performed by a β-D-glucoside glucohydrolase; both these functions appear to reside in the same molecule.


1976 ◽  
Vol 36 (1) ◽  
pp. 101-112 ◽  
Author(s):  
I. Bremner ◽  
N. T. Davies

1. A study has been made by gel-filtration techniques of the soluble copper- and zinc-binding proteins in rat liver after both intraperitoneal injection of Cu and dietary Cu supplementation.2. Liver Cu and Zn concentrations increased after injection of Cu, both metals accumulating in the cytosol, mainly in a fraction with an apparent molecular weight of (about 12 000)3. When Zn-deficient rats were injected with Cu, there was little change in liver Zn concentration and the occurrence of Cu in the low-molecular-weight form (about 12 000) was more transient. At most periods after injection, Cu accumulated mainly in a fraction with a molecular weight greater than 65 000.4. When the rats were Cu-loaded by dietary supplementation, virtually no Cu or Zn was found in the low-molecular-weight form in Zn-deficient rats, although they were found in the Zn-supplemented animals.5. The results suggest that Zn is essential for the accumulation of Cu in this form, but not for Cu to stimulate production of the metal-binding protein by a process requiring active protein synthesis.


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