Topography of membrane proteins — determination of regions exposed to the aqueous phase

1986 ◽  
pp. 129-151
Author(s):  
Paul A. Hargrave
Keyword(s):  
Membrane Proteins ◽  
Aqueous Phase

Determination of Dimetridazole and Ipronidazole in Feeds at Cross-Contamination Levels

1988 ◽  
Vol 71 (3) ◽  
pp. 474-477 ◽  
Author(s):  
Duane D Hughes
Keyword(s):  
Thin Layer ◽  
Rapid Method ◽  
Aqueous Phase ◽  
Borate Buffer ◽  
Cross Contamination ◽  
Chromatographic System ◽  
Arsanilic Acid ◽  
Contamination Levels ◽  
Benzene Extract

Abstract A rapid method for the determination of dimetridazole and ipronidazole in feeds is described. The compounds are extracted from a borate buffer (pH 8.65) with benzene, partitioned into IN HC1, and then partitioned back into benzene from a basic aqueous phase. The benzene extract is concentrated and injected onto a nonpolar (Apiezon L) gas chromatographic column for determination by 63Ni electroncapture detection. Recoveries from feeds of various composition, spiked at 0.2 ppm with both dimetridazole and ipronidazole, ranged from 70 to 115%; for the same feeds spiked at 1 ppm or more, the recoveries were greater than 80%. Carbadox, furazolidone, levamisole, oxytetracycline, chlortetracycline, sulfamethazine, sulfaquinoxaline, arsanilic acid, piperazine, penicillin, and commonly added vitamins and minerals do not interfere. A 2-dimensional thin layer chromatographic system is presented as a means of additional identification.

Size Determination of Membrane Proteins

1975 ◽  
Vol 3 (5) ◽  
pp. 593-596
Author(s):  
A. H. MADDY
Keyword(s):  
Membrane Proteins ◽  
Size Determination

scholarly journals Tricks of the trade used to accelerate high-resolution structure determination of membrane proteins

FEBS Letters ◽  
2010 ◽  
Vol 584 (12) ◽  
pp. 2539-2547 ◽  
Author(s):  
Yo Sonoda ◽  
Alex Cameron ◽  
Simon Newstead ◽  
Hiroshi Omote ◽  
Yoshinori Moriyama ◽  
...  
Keyword(s):  
High Resolution ◽  
Membrane Proteins ◽  
Structure Determination ◽  
High Resolution Structure ◽  
Resolution Structure

Quantitative determination of aqueous-phase ozone by chemiluminescence using indigo-5,5'-disulfonate

1989 ◽  
Vol 61 (6) ◽  
pp. 619-623 ◽  
Author(s):  
Koji. Takeuchi ◽  
Takashi. Ibusuki
Keyword(s):  
Quantitative Determination ◽  
Aqueous Phase

scholarly journals High-Resolution NMR Determination of the Dynamic Structure of Membrane Proteins

2016 ◽  
Vol 55 (35) ◽  
pp. 10518-10521 ◽  
Author(s):  
Mariusz Jaremko ◽  
Łukasz Jaremko ◽  
Saskia Villinger ◽  
Christian D. Schmidt ◽  
Christian Griesinger ◽  
...  
Keyword(s):  
High Resolution ◽  
Membrane Proteins ◽  
Dynamic Structure ◽  
High Resolution Nmr

HPLC Determination of Furfural after Preliminary Extraction to Aqueous Phase

2007 ◽  
Vol 30 (14) ◽  
pp. 2081-2093 ◽  
Author(s):  
Hossein Sid Kalal ◽  
Mohamad Khayatzadeh Mahani ◽  
Mohamad Ghanadi Maragheh ◽  
Marzieh Chaloosi
Keyword(s):  
Aqueous Phase ◽  
Hplc Determination ◽  
Preliminary Extraction

scholarly journals Glycosyl-phosphatidylinositol-anchored membrane proteins can be distinguished from transmembrane polypeptide-anchored proteins by differential solubilization and temperature-induced phase separation in Triton X-114

1991 ◽  
Vol 280 (3) ◽  
pp. 745-751 ◽  
Author(s):  
N M Hooper ◽  
A Bashir
Keyword(s):  
Phase Separation ◽  
Membrane Proteins ◽  
Aqueous Phase ◽  
Hydrophobic Membrane ◽  
Rich Phase ◽  
Glycosyl Phosphatidylinositol ◽  
Ionic Detergent ◽  
Membrane Spanning ◽  
Triton X ◽  
Insoluble Pellet

Treatment of kidney microvillar membranes with the non-ionic detergent Triton X-114 at 0 degrees C, followed by low-speed centrifugation, generated a detergent-insoluble pellet and a detergent-soluble supernatant. The supernatant was further fractionated by phase separation at 30 degrees C into a detergent-rich phase and a detergent-depleted or aqueous phase. Those ectoenzymes with a covalently attached glycosyl-phosphatidylinositol (G-PI) membrane anchor were recovered predominantly (greater than 73%) in the detergent-insoluble pellet. In contrast, those ectoenzymes anchored by a single membrane-spanning polypeptide were recovered predominantly (greater than 62%) in the detergent-rich phase. Removal of the hydrophobic membrane-anchoring domain from either class of ectoenzyme resulted in the proteins being recovered predominantly (greater than 70%) in the aqueous phase. This technique was also applied to other membrane types, including pig and human erythrocyte ghosts, where, in both cases, the G-PI-anchored acetylcholinesterase partitioned predominantly (greater than 69%) into the detergent-insoluble pellet. When the microvillar membranes were subjected only to differential solubilization with Triton X-114 at 0 degrees C, the G-PI-anchored ectoenzymes were recovered predominantly (greater than 63%) in the detergent-insoluble pellet, whereas the transmembrane-polypeptide-anchored ectoenzymes were recovered predominantly (greater than 95%) in the detergent-solubilized supernatant. Thus differential solubilization and temperature-induced phase separation in Triton X-114 distinguished between G-PI-anchored membrane proteins, transmembrane-polypeptide-anchored proteins and soluble, hydrophilic proteins. This technique may be more useful and reliable than susceptibility to release by phospholipases as a means of identifying a G-PI anchor on an unpurified membrane protein.

Determination of Tin in Canned Fruits and Vegetables by Atomic Absorption Spectrometry and Liquid–Liquid Extraction

1994 ◽  
Vol 77 (6) ◽  
pp. 1627-1630 ◽  
Author(s):  
Ana M Martín ◽  
Mercedes Sánchez ◽  
Pedro Espinosa ◽  
Gracia Bagur
Keyword(s):  
Aqueous Phase ◽  
Fruits And Vegetables ◽  
Methyl Ketone ◽  
Absorption Spectrometry ◽  
Liquid Extraction ◽  
Acid Complex ◽  
Liquid Liquid Extraction ◽  
Relative Standard ◽  
Good Agreement

Abstract A method was developed for the determination of tin based on the extraction of its 5,5-methylenedisalicylohydroxamic acid complex with 1.09M isobutyl methyl ketone in tributyl phosphate. After the samples were treated with nitric and hydrochloric acid, the aqueous phase was made to 0.05M in perchloric acid. When the ratio of aqueous phase to organic phase was 4:1 (v/v), the detection limit and the relative standard deviation (n = 7,50 μg tin) were 0.20 μg/mL and 0.9%, respectively. The proposed method was applied to the analysis of tin in canned fruits and vegetables. The results were in good agreement with those obtained by the phenylfluorone method.

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