scholarly journals STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS

1944 ◽  
Vol 27 (3) ◽  
pp. 201-232 ◽  
Author(s):  
A. S. C. Lawrence ◽  
Joseph Needham ◽  
Shih-Chang Shen
Keyword(s):  
Simultaneous Determination ◽  
Surface Film ◽  
Flow Birefringence ◽  
Bulk Phase ◽  
Protein Solutions ◽  
Dilute Solutions ◽  
General Behaviour ◽  
Anomalous Viscosity

1. A coaxial viscosimeter which permits the simultaneous determination of relative and anomalous viscosity and of flow-birefringence is described. Flow-anomaly and flow-birefringence are regarded as characteristic of elongated micelles and molecules. 2. Such methods have been applied to dilute solutions of proteins. The conditions under which the coaxial (Couette) viscosimeter measures the viscosity of the bulk phase and the surface film phase respectively have been investigated and are described. 3. The general behaviour of protein solutions subjected to shear is summarised.

scholarly journals STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS

1944 ◽  
Vol 27 (3) ◽  
pp. 233-271 ◽  
Author(s):  
A. S. C. Lawrence ◽  
Margaret Miall ◽  
Joseph Needham ◽  
Shih-Chang Shen
Keyword(s):  
Film Flow ◽  
Surface Film ◽  
Mosaic Disease ◽  
Flow Birefringence ◽  
Bulk Phase ◽  
Protein Solutions ◽  
Amphibian Embryo ◽  
Anomalous Viscosity ◽  
Group A ◽  
Group B

1. An extensive investigation has been made of protein particle shape using the methods of flow-birefringence and anomalous viscosity measurement in the coaxial cell. 2. As a result of investigations on a number of proteins, it is concluded that they may be divided into four groups. Group A consists of those which show flow-anomaly both in the bulk phase and in the surface film. These also show flow-birefringence in the bulk phase. Examples: tobacco mosaic disease virus nucleoprotein; myosin. Though corpuscular proteins, they have elongated particles before denaturation. Group B consists of those which show flow-anomaly only (in the first instance) in the surface film, and no flow-birefringence in the bulk phase. They are probably close to spherical in shape in solution, but form elongated particles as they denature in the surface film. After this process has been completed, they may show flow-anomaly also in the bulk phase. Some proteins show flow-anomaly in the surface film immediately it forms, others only show it after a certain time has elapsed for the building up of the film. We designate the former as group B1 and the latter as group B2. Group B1, immediate surface film flow-anomaly. Examples: serum euglobulin, amphibian embryo euglobulin b. Group B2, slowly appearing surface film flow-anomaly. After the film has once been fully formed and then dispersed by shaking, the solution may have the properties of that of a protein in group B1; i.e., anomalous flow in the film may occur immediately on testing in the viscosimeter. Examples: avian ovalbumin, amphibian embryo pseudoglobulin. Group C consists of those proteins which show flow-anomaly neither in the bulk phase nor in the surface film, under the conditions used by us. They are probably close to spherical in shape. Examples: insulin, methaemoglobin, amphibian embryo euglobulin c, mucoproteins. 3. The theoretical significance of protein fibre molecules, whether native or formed by denaturation in the living cell, is discussed, especially in relation to experimental morphology and cytology.

scholarly journals STUDIES ON THE ANOMALOUS VISCOSITY AND FLOW-BIREFRINGENCE OF PROTEIN SOLUTIONS

1944 ◽  
Vol 27 (4) ◽  
pp. 355-399 ◽  
Author(s):  
Mary Dainty ◽  
Arnost Kleinzeller ◽  
A. S. C. Lawrence ◽  
Margaret Miall ◽  
Joseph Needham ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Cell Structure ◽  
Relative Viscosity ◽  
Flow Birefringence ◽  
Protein Solutions ◽  
Muscle Physiology ◽  
Anomalous Viscosity ◽  
Full Effect ◽  
Competitive Inhibitors ◽  
Other Substances

1. An investigation of the physicochemical properties of myosin has been carried out. Prepared under standard conditions, the ratio of flow-birefringence to protein concentration is uniform. The effect of electrolytes, pH, and urea on the flow-birefringence and viscosity (relative and anomalous) of myosin has been examined. 2. Decrease or abolition of flow-birefringence does not necessarily imply far reaching denaturation, since such effects can be reversed by a variety of means. 3. When a myosin solution is treated with adenosinetriphosphate, its flow-birefringence is decreased (average 48 per cent), its anomalous viscosity is retained, and its relative viscosity is decreased (average 14 per cent). The full effect of adenosinetriphosphate is obtained at 0.004 M; a molarity very much less than that of other substances which decrease the flow-birefringence of myosin. 4. The changes in the physicochemical properties of myosin brought about by adenosinetriphosphate are spontaneously reversible, and are connected with the enzymatic action of the protein as adenosinetriphosphatase. 5. Effects similar to those of adenosinetriphosphate on the physicochemical properties of purified myosin have been obtained so far only with inosinetriphosphate. 6. Inorganic phosphate is split off by myosin from inosinetriphosphate as well as from adenosinetriphosphate. Inorganic triphosphate is split by 1 to 2 per cent solution of three times precipitated myosin. 7. Adenosinediphosphate and inorganic triphosphate act as competitive inhibitors with adenosinetriphosphate, blocking the fall of flow-birefringence. 8. The implications of the results, and the conception of active enzymic groups attached to proteins participating in cell structure, whether contractile or non-contractile, are discussed in relation to present views on muscle physiology and other biological problems.

A general computer program for the extended plate overlap algorithm

1978 ◽  
Vol 48 ◽  
pp. 287-293 ◽  
Author(s):  
Chr. de Vegt ◽  
E. Ebner ◽  
K. von der Heide
Keyword(s):  
Computer Program ◽  
Simultaneous Determination ◽  
General Computer Program ◽  
General Computer

In contrast to the adjustment of single plates a block adjustment is a simultaneous determination of all unknowns associated with many overlapping plates (star positions and plate constants etc. ) by one large adjustment. This plate overlap technique was introduced by Eichhorn and reviewed by Googe et. al. The author now has developed a set of computer programmes which allows the adjustment of any set of contemporaneous overlapping plates. There is in principle no limit for the number of plates, the number of stars, the number of individual plate constants for each plate, and for the overlapping factor.

Simultaneous determination of seven compounds in Euronymus alatus by HPLC-DAD

Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
YS Jung ◽  
JB Weon ◽  
CJ Ma
Keyword(s):  
Simultaneous Determination
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