Heat-stable pullulanase from Bacillus acidopullulyticus : characterization and refolding after guanidinium chloride-induced unfolding

Extremophiles ◽  
1999 ◽  
Vol 3 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Miglena E. Stefanova ◽  
Ruth Schwerdtfeger ◽  
Garabed Antranikian ◽  
R. Scandurra
Keyword(s):  
Guanidinium Chloride ◽  
Heat Stable ◽  
Bacillus Acidopullulyticus

scholarly journals A fluorimetric study of the role of calcium ions in the stability of thermolysin

1977 ◽  
Vol 165 (3) ◽  
pp. 539-545 ◽  
Author(s):  
Angelo Fontana ◽  
Claudio Vita ◽  
Enrico Boccu' ◽  
Francesco M. Veronese
Keyword(s):  
Calcium Ions ◽  
Fluorescence Emission ◽  
Protein Molecule ◽  
Fluorescence Emission Spectrum ◽  
Guanidinium Chloride ◽  
Emission Maximum ◽  
Heat Stable ◽  
Tryptophan Residues ◽  
The Stability

1. Fluorimetric techniques were used to characterize the environment of tryptophan residues in thermolysin and apo-thermolysin. The apo-thermolysin was obtained by dissolving the enzyme in the presence of 10mm-EDTA, which removed the functional Zn2+ ion and the four Ca2+ ions/molecule from the enzyme. 2. At 25°C in aqueous solution the fluorescence-emission spectrum of the native holoenzyme, on excitation at 290nm, was essentially characteristic of tryptophan, with an emission maximum at 333nm. The emission maximum of the apoenzyme is red-shifted to 338nm and the relative intensity of fluorescence is decreased by 10%, both effects indicating some unfolding of the protein molecule, with the indole groups being transferred to a more hydrophilic environment. 3. Fluorescence quenching studies using KI, N′-methylnicotinamide hydrochloride and acrylamide indicated a more open structure in the apoenzyme, with the tryptophan residues located in a negatively charged environment. 4. The thermal properties of the apoenzyme, as monitored by fluorescence-emission measurements, are dramatically changed with respect to the native holoenzyme. In fact, whereas the native enzyme is heat-stable up to about 80°C, for the apoenzyme a thermal transition is observed near 48°C. The apoenzyme is also unstable to the action of unfolding agents such as urea and guanidinium chloride, much as for other globular proteins from mesophilic organisms. 5. The functional Zn2+ ion does not contribute noticeably to the stability of thermolysin. 6. It is concluded that a major role in the structural stability of thermolysin is played by the Ca2+ ions, which have a bridging function within this disulphide-free protein molecule.

Heat stable toxin of E. coli (STa) stimulates duodenal mucosal bicarbonate secretion in cystic fibrosis knockout mice

2001 ◽  
Vol 120 (5) ◽  
pp. A137-A137
Author(s):  
D CHILDS ◽  
D CROMBIE ◽  
V PRATHA ◽  
Z SELLERS ◽  
D HOGAN ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Knockout Mice ◽  
Bicarbonate Secretion ◽  
E Coli ◽  
Heat Stable

Plasminogen Activator and Plasminogen Activator Inhibitor Associated with Granulomatous Inflammation: A Study with Murine Leprosy

1984 ◽  
Vol 52 (03) ◽  
pp. 243-249 ◽  
Author(s):  
S Izaki ◽  
T Hibino ◽  
Y Isozaki ◽  
P S Hsu ◽  
M Izaki ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Soluble Fraction ◽  
Proteinase Inhibitors ◽  
Granulomatous Inflammation ◽  
Serine Proteinase ◽  
Plasminogen Activator Inhibitor ◽  
Tissue Type ◽  
Weakly Alkaline ◽  
Heat Stable ◽  
Type Plasminogen Activator

SummaryPlasminogen activator that is associated with the development of hypersensitivity granulomas (gPA) was partially purified from a saline soluble fraction of murine lepromas elicited in “resistant” mice, C57BL/6N. The gPA was shown to consist of two subspecies (23,000 and 48,000 in molecular weight) with essentially identical enzymologic properties. The gPA was found to be a relatively heat stable weakly alkaline serine proteinase with trypsin-like characteristics in the specificity for synthetic substrates and proteinase inhibitors. It showed a high affinity for H- D-Ile-Pro-Arg-pNA (Km = 1.4 × 10-4 M) H-D-Val-Leu-Lys- pNA (Km = 5.2 × 10-4 M), and L-pyroGlu-Gly-Arg-pNA (Km = 9.3 × 10-4 M). The gPA did not demonstrate antigenic cross reaction with urokinase-type or tissue-type plasminogen activator.Two distinct enzymatic regulators of the gPA were also demonstrated in the saline soluble fraction of the hypersensitivity granulomas. The gPA and its regulation are assumed to be correlated with macrophage activation in the hypersensitivity granulomas

The Heat-Stable Enterotoxin(s) of Yersinia enterocolitica in Foods

1984 ◽  
Author(s):  
Stephen L. Taylor ◽  
Michael P. Doyle ◽  
Alison R. Behling
Keyword(s):  
Yersinia Enterocolitica ◽  
Heat Stable

scholarly journals Genome-wide CRISPR/Cas9 screening identifies CARHSP1 responsible for radiation resistance in glioblastoma

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Guo-dong Zhu ◽  
Jing Yu ◽  
Zheng-yu Sun ◽  
Yan Chen ◽  
Hong-mei Zheng ◽  
...  
Keyword(s):  
Cold Shock ◽  
Mrna Level ◽  
Critical Role ◽  
Inflammatory Signaling ◽  
Heat Stable ◽  
Genome Wide ◽  
Attractive Therapeutic Target ◽  
Heat Stable Protein ◽  
Signaling Activation ◽  
Shock Proteins

AbstractGlioblastomas (GBM) is the most common primary malignant brain tumor, and radiotherapy plays a critical role in its therapeutic management. Unfortunately, the development of radioresistance is universal. Here, we identified calcium-regulated heat-stable protein 1 (CARHSP1) as a critical driver for radioresistance utilizing genome-wide CRISPR activation screening. This is a protein with a cold-shock domain (CSD)-containing that is highly similar to cold-shock proteins. CARHSP1 mRNA level was upregulated in irradiation-resistant GBM cells and knockdown of CARHSP1 sensitized GBM cells to radiotherapy. The high expression of CARHSP1 upon radiation might mediate radioresistance by activating the inflammatory signaling pathway. More importantly, patients with high levels of CARHSP1 had poorer survival when treated with radiotherapy. Collectively, our findings suggested that targeting the CARHSP1/TNF-α inflammatory signaling activation induced by radiotherapy might directly affect radioresistance and present an attractive therapeutic target for GBM, particularly for patients with high levels of CARHSP1.

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