Studies on the Anomalous Viscosity and Flow-Birefringence of Protein Solutions

Miall, Margaret; Needham, Joseph; Shen, Shih‐Chang

doi:10.1085/jgp.27.3.233

Cited by 26 publications

(1 citation statement)

References 29 publications

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“…Binkley's results are in agreement with those of Mommaerts (123,124) for myosin and the earlier results of von Muralt and Edsall (125) for the actomyosin complex (denoted as myosin in the earlier terminology used by von Muralt and Edsall). An extensive study of the effects of various agents on the flow birefringence properties of myosin solutions has been carried out by Lawrence and coworkers (32,116,117,126).…”

Section: Comparison With Other Methodsmentioning

confidence: 99%

Flow Birefringence in Solutions of Macromolecules.

Cerf¹,

Scheraga²

1952

Chem. Rev.

119

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Section: Comparison With Other Methodsmentioning

confidence: 99%

Flow Birefringence in Solutions of Macromolecules.

Cerf¹,

Scheraga²

1952

Chem. Rev.

119

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Action of shear on enzymes: Studies with catalase and urease

Thomas

Dunnill

1979

Biotech & Bioengineering

112

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SummaryIntermittent shear was applied to approximately 1 mg/ml solutions of bovine liver catalase in a coaxial cylindrical viscometer at temperatures from 20 to 60°C and shear rates up to 683 sec-I. The viscometer was sealed to prevent evaporation. Up to 40°C there were no activity losses during 3 hr total shearing. Above 40°C shearing reduced losses due to thermal inactivation, possibly by interfering with precipitation. At 3440 sec-l and 40°C fine precipitates formed but little activity was lost. No activity losses were found with experimentai conditions under which Taylor vortexing occurred, nor when shear stresses were increased up 57 times by adding glycerol to raise the viscosity. There were no significant losses in a capillary rheometer at shear rates up to 106 sec-*. When low concentration (6 pgiml) catalase solutions were sheared there was little loss in sealed systems, but there were losses in "open" systems even in low-temperature nonshear experiments. Although there were no losses with 1 mg/ml solutions, 6 pgiml catalase solutions from an alternative source did lose activity in sealed systems but much less than expected from previously published work. Approximately 1 mg/ml jack bean urease solutions were sheared in the sealed system at 23°C and 683 sec-I for 3 hr. N o losses were found. No evidence of temporary or permanent inactivation was found with 28 pgiml solutions sheared in the presence of urea. Shear forces alone were not found to be as effective in causing enzyme inactivation as is generally believed and alternative mechanisms for damage are discussed.

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Glycogen utilization by the amphibian gastrula in relation to invagination and induction

Jaeger

1945

J. Cell. Comp. Physiol.

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A'cw Por7; C i t y THREE FIGURESThe utilization of glycogen by the amphibian embryo has been in the past a subject of repeated experimental attack. Particular attention has been given t o glycogen utilization by the gastrula, for it was hoped that some correlation might be drawn between carbohydrate combustion and the phenomenon of induction. A brief survey of the literature will indicate however that doubts must attach to experiments purporting to prove regional differences in glycolysis of the gastrula. Crucial experiments morever are lacking whose specific objective was to test the relation between glycogen utilization and the various concomitant events which comprise the gastrulation process.Early studies of glycogen in the amphibian embryo depended on a qualitative, non-specific color reaction with Lugol's solution. Woerdcman ('33a), using such a test on urodele gastrulae, found at the dorsal lip of the blastopore a distinct boundary between uninvaginated presumptive chorda-mesoderm, rich in granules that stained brown with iodine, and invaginated dorsal lip material, almost entirely free of such glycogen granules.' Raven ( '33, '35) published histochemical results suggesting that the disappearance of glycogen from invagnating cells is not an autonomous event, nor a result of the new environment into which invagination carries the cells, but rather is dependent upon the "Einrollung" process itself. The observations of Woerdeman and Raven were qualitative, and had to be accepted with reservations that bear upon any histocheniical test which may be influenced by subjective errors in estimating comparative intensities of color. Pasteels ( '36) furthermore attributed the apparent glycolysis to faulty methods of fixation.Whether this embryonic glycogen is actually contained in granules, or whether it is of the submicroscopic " p r t i r n l a t e " type described for liver cells by Lazarow ('42) and in aphids (Loring and Pierce, '43), does not affect the significance of Woerdeman's findings. Since however iodine solutions coagulate proteins (Lazarow, '42) the granular appearance of glycogen hi these histochemical tests mag have been an artefact. 97

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Studies on the Anomalous Viscosity and Flow-Birefringence of Protein Solutions

Cited by 26 publications

References 29 publications

Flow Birefringence in Solutions of Macromolecules.

Flow Birefringence in Solutions of Macromolecules.

Action of shear on enzymes: Studies with catalase and urease

Glycogen utilization by the amphibian gastrula in relation to invagination and induction

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