scholarly journals The Structure of Surface-Denatured Protein. I. Molecular Weight and Surface Area of Horse Serum Albumin Molecule

1952 ◽  
Vol 25 (1) ◽  
pp. 7-10 ◽  
Author(s):  
Kazutomo Imahori
1939 ◽  
Vol 23 (2) ◽  
pp. 177-184 ◽  
Author(s):  
Erich Peters ◽  
George Saslow

Estimation of the molecular weight of horse serum albumin from the osmotic pressure of solutions containing 0.713 to 5.12 gm. per 100 cc. shows that the Hepp osmometer yields the same values as the standard simple osmometer of Adair. Accuracy and precision of the instrument decrease noticeably at concentrations of albumin less than 0.7 gm. per 100 cc. A determination in duplicate can be carried out with this instrument in less than 2 hours. The instrument is easily operated.


1992 ◽  
Vol 262 (3) ◽  
pp. H728-H733
Author(s):  
D. L. Roerig ◽  
C. A. Dawson ◽  
S. B. Ahlf ◽  
R. D. Bongard ◽  
J. H. Linehan ◽  
...  

We investigated the uptake and efflux of Blue Dextran in the isolated perfused rabbit lung. Blue Dextran is a high-molecular-weight glucose polymer (original mol wt 2 x 10(6) g/mol) containing covalently bonded Reactive Blue 2 dye (approximately mmol/g dextran). This blue dye is known for its high binding affinity to a wide variety of proteins, with a particularly high affinity for serum albumin. In isolated rabbit lungs perfused with a protein-free perfusate, both bolus injection and recirculation of Blue Dextran revealed a rapid saturable uptake. Once the lungs were loaded with Blue Dextran, efflux of the Blue Dextran accumulated in the lungs could be induced by addition of bovine serum albumin (BSA) to the recirculating perfusate. The amount of BSA-induced efflux of Blue Dextran from the lung was independent of perfusate flow. When the left pulmonary artery was ligated after the lungs had been loaded with Blue Dextran, the dye-induced BSA efflux was only about 50% of normal. Release of the ligature so that both lungs were perfused resulted in efflux of the remaining Blue Dextran. The combination of high airway pressure and low flow also reduced the dye efflux, and the effect was reversed by reducing the airway pressure. With the assumption that the high average molecular weight of Blue Dextran confines this molecule to interaction with proteins on the vascular surface, the results of this study suggest that Blue Dextran uptake and its BSA-induced efflux are proportional to the perfused vascular surface area in the lung.


1943 ◽  
Vol 78 (1) ◽  
pp. 1-8 ◽  
Author(s):  
John O. Erickson ◽  
Hans Neurath

Comparative immunological measurements have been carried out on crystalline horse serum albumin in the native state and after regeneration from 8 M urea solutions. The mean antigenic activity of the regenerated protein has been found to be less than 10 per cent of that of the native, whereas both antigens proved to be immunologically equivalent. The problem of the relation between protein denaturation and immunological activity has been considered and discussed on the basis of known physical and chemical differences between native and denatured protein.


1941 ◽  
Vol 141 (3) ◽  
pp. 999-1000
Author(s):  
Erwin Brand ◽  
Beatrice Kassell
Keyword(s):  

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3321
Author(s):  
Katarzyna Kurpet ◽  
Rafał Głowacki ◽  
Grażyna Chwatko

Biothiols are extremely powerful antioxidants that protect cells against the effects of oxidative stress. They are also considered relevant disease biomarkers, specifically risk factors for cardiovascular disease. In this paper, a new procedure for the simultaneous determination of human serum albumin and low-molecular-weight thiols in plasma is described. The method is based on the pre-column derivatization of analytes with a thiol-specific fluorescence labeling reagent, monobromobimane, followed by separation and quantification through reversed-phase high-performance liquid chromatography with fluorescence detection (excitation, 378 nm; emission, 492 nm). Prior to the derivatization step, the oxidized thiols are converted to their reduced forms by reductive cleavage with sodium borohydride. Linearity in the detector response for total thiols was observed in the following ranges: 1.76–30.0 mg mL−1 for human serum albumin, 0.29–5.0 nmol mL−1 for α-lipoic acid, 1.16–35 nmol mL−1 for glutathione, 9.83–450.0 nmol mL−1 for cysteine, 0.55–40.0 nmol mL−1 for homocysteine, 0.34–50.0 nmol mL−1 for N-acetyl-L-cysteine, and 1.45–45.0 nmol mL−1 for cysteinylglycine. Recovery values of 85.16–119.48% were recorded for all the analytes. The developed method is sensitive, repeatable, and linear within the expected ranges of total thiols. The devised procedure can be applied to plasma samples to monitor biochemical processes in various pathophysiological states.


1938 ◽  
Vol 21 (3) ◽  
pp. 335-366 ◽  
Author(s):  
John H. Northrop

1. A method for isolating a nucleoprotein from lysed staphylococci culture is described. 2. It is homogeneous in the ultracentrifuge and has a sedimentation constant of 650 x 10–13 cm. dyne–1 sec.–1, corresponding to a molecular weight of about 300,000,000. 3. The diffusion coefficient varies from about 0.001 cm.2/day in solutions containing more than 0.1 mg. protein/ml. to 0.02 in solutions containing less than 0.001 mg. protein/ml. The rate of sedimentation also decreases as the concentration decreases. It is suggested, therefore, that this protein exists in various sized molecules of from 500,000–300,000,000 molecular weight, the proportion of small molecules increasing as the concentration decreases. 4. This protein is very unstable and is denatured by acidity greater than pH 5.0, by temperature over 50°C. for 5 minutes. It is digested by chymo-trypsin but not by trypsin. 5. The loss in activity by heat, acid, and chymo-trypsin digestion is roughly proportional to the amount of denatured protein formed under these conditions. 6. The rate of diffusion of the protein is the same as that of the active agent. 7. The rate of sedimentation of the protein is the same as that of the active agent. 8. The loss in activity when susceptible living or dead bacteria are added to a solution of the protein is proportional to the loss in protein from the solution. Non-susceptible bacteria remove neither protein nor activity. 9. The relative ultraviolet light absorption, as determined directly, agrees with that calculated from Gates' inactivation experiments in the range of 2500–3000 Å. u. but is somewhat greater in the range of 2000–2500 Å. u. 10. Solubility determinations showed that most of the preparations contained at least two proteins, one being probably the denatured form of the other. Two preparations were obtained, however, which had about twice the specific activity of the earlier ones and which gave a solubility curve approximating that of a pure substance. 11. It is suggested that the formation of phage may be more simply explained by analogy with the autocatalytic formation of pepsin and trypsin than by analogy with the far more complicated system of living organisms.


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