Isolation and preliminary characterization of an extracellular protease of Cytophaga sp.

1971 ◽  
Vol 17 (9) ◽  
pp. 1207-1216 ◽  
Author(s):  
J. Christison ◽  
S. M. Martin
Keyword(s):  
Basic Protein ◽  
Close Contact ◽  
Deae Cellulose ◽  
Extracellular Protease ◽  
Bacterial Cells ◽  
Selective Precipitation ◽  
Slime Layer ◽  
Degradative Enzymes ◽  
Protein Enzyme

The extracellular protease(s) of Cytophaga sp. is present naturally as a complex with acidic polysaccharides of the slime layer. The protein was separated from the slime by selective precipitation of the polysaccharide with a cationic detergent and the enzyme was purified about 100-fold by precipitation with alcohol and by chromatography on DEAE-cellulose. Inhibitor studies indicated that this alkaline protease was not of the trypsin/chymotrypsin type. Ca2+ had a strong stabilizing effect on the enzyme. The complex of basic protein (enzyme) and acidic slime polysaccharides has led to the conclusion that the enzyme is perhaps not truly extracellular but rather is surface bound. The slime layer would appear to have a role in attaching the bacterial cells to insoluble substrates as well as ensuring that degradative enzymes are kept in close contact with the substrate.

scholarly journals Zinc Oxide and Silver Nanoparticle Effects on Intestinal Bacteria

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2489
Author(s):  
Ami Yoo ◽  
Mengshi Lin ◽  
Azlin Mustapha
Keyword(s):  
Electron Microscopy ◽  
Zinc Oxide ◽  
Morphological Changes ◽  
Intestinal Bacteria ◽  
Bacterial Cells ◽  
Ag Nps ◽  
Zno Nps ◽  
Bifidobacterium Animalis ◽  
Transmission Electron

The application of nanoparticles (NPs) for food safety is increasingly being explored. Zinc oxide (ZnO) and silver (Ag) NPs are inorganic chemicals with antimicrobial and bioactive characteristics and have been widely used in the food industry. However, not much is known about the behavior of these NPs upon ingestion and whether they inhibit natural gut microflora. The objective of this study was to investigate the effects of ZnO and Ag NPs on the intestinal bacteria, namely Escherichia coli, Lactobacillus acidophilus, and Bifidobacterium animalis. Cells were inoculated into tryptic soy broth or Lactobacilli MRS broth containing 1% of NP-free solution, 0, 12, 16, 20 mM of ZnO NPs or 0, 1.8, 2.7, 4.6 mM Ag NPs, and incubated at 37 °C for 24 h. The presence and characterization of the NPs on bacterial cells were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). Membrane leakage and cell viability were assessed using a UV-visible spectrophotometer and confocal electron microscope, respectively. Numbers of treated cells were within 1 log CFU/mL less than those of the controls for up to 12 h of incubation. Cellular morphological changes were observed, but many cells remained in normal shapes. Only a small amount of internal cellular contents was leaked due to the NP treatments, and more live than dead cells were observed after exposure to the NPs. Based on these results, we conclude that ZnO and Ag NPs have mild inhibitory effects on intestinal bacteria.

Selective precipitation and characterization of lignin–carbohydrate complexes (LCCs) from Eucalyptus

Planta ◽  
2018 ◽  
Vol 247 (5) ◽  
pp. 1077-1087 ◽  
Author(s):  
Bao-Cheng Zhao ◽  
Ji-Dong Xu ◽  
Bo-Yang Chen ◽  
Xue-Fei Cao ◽  
Tong-Qi Yuan ◽  
...  
Keyword(s):  
Selective Precipitation

Myelin basic protein: Structural characterization of spherulites formation and preventive action of trehalose

2013 ◽  
Vol 57 ◽  
pp. 63-68 ◽  
Author(s):  
Cinzia Di Salvo ◽  
Davide Barreca ◽  
Giuseppina Laganà ◽  
Marcella di Bella ◽  
Ester Tellone ◽  
...  
Keyword(s):  
Myelin Basic Protein ◽  
Structural Characterization ◽  
Basic Protein ◽  
Preventive Action

Characterization of an isozyme of S-adenosylmethionine synthetase from rat liver

1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Enzymatic Synthesis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Aromatic Amino Acids ◽  
Adenosylmethionine Synthetase ◽  
Cellulose Column

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.

Characterization of lignins obtained by selective precipitation

2009 ◽  
Vol 68 (2) ◽  
pp. 193-198 ◽  
Author(s):  
A. García ◽  
A. Toledano ◽  
L. Serrano ◽  
I. Egüés ◽  
M. González ◽  
...  
Keyword(s):  
Selective Precipitation

DEAE cellulose chromatographic characterization of canine serum

1980 ◽  
Vol 3 (4) ◽  
pp. 525-534
Author(s):  
Caroline C Whitacre ◽  
Virginia S Mehl ◽  
Raymond W Lang
Keyword(s):  
Deae Cellulose ◽  
Chromatographic Characterization ◽  
Canine Serum

scholarly journals Androgen-sensitive spermine-binding protein of rat ventral prostate. Purification of the protein and characterization of the hormonal effect

1979 ◽  
Vol 184 (2) ◽  
pp. 431-440 ◽  
Author(s):  
G Mezzetti ◽  
R Loor ◽  
S Liao
Keyword(s):  
Binding Protein ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Binding Activity ◽  
Ventral Prostate ◽  
Hormonal Effect ◽  
Rat Ventral Prostate ◽  
Acidic Fraction ◽  
Androgen Effect

The rat ventral prostate contains a cytosol protein that can non-covalently bind spermine much more tightly than spermidine or other natural diamines. The protein has been purified to homogeneity, as judged by electrophoresis in urea- and sodium dodecyl sulphate-containing polyacrylamide gels. The protein, with or without spermine bound to it, sediments at 3 S in a sucrose gradient with or without 0.4 M-KCl. The molecular weight of the protein is about 30 000. Each molecule of the binding protein can bind one molecule of spermine. In the prostate of rats injected with cycloheximide, the protein appears to have a half-life of about 3.5 h. The spermine-binding activity of an acidic fraction obtained by DEAE-cellulose chromatography of the prostate cytosol proteins is reduced by about 40–60% within 20–40 h after castration. This effect is reversed very rapidly within 15–30 min by intraperitoneal injection of 5 alpha-dihydrotestosterone. The hormonal effect is androgen-specific and is not mimicked by dexamethasone or oestradiol-17 beta. The androgen effect was reduced significantly when rats were injected with cycloheximide or actinomycin D, suggesting that the acidic protein may be one of the earliest proteins induced by androgen in the rat ventral prostate.

Sign in / Sign up

Export Citation Format

Share Document