The determination of molecular weights of macromolecules from measurements of osmotic pressure

Electron microscopic methods have been applied increasingly during the past fifteen years, to problems in structural molecular biology. Used in conjunction with physical chemical methods and/or Fourier methods of analysis, they constitute powerful tools for determining sizes, shapes and modes of aggregation of biopolymers with molecular weights greater than 50, 000. However, the application of the e.m. to the determination of very fine structure approaching the limit of instrumental resolving power in biological systems has not been productive, due to various difficulties such as the destructive effects of dehydration, damage to the specimen by the electron beam, and lack of adequate and specific contrast. One of the most satisfactory methods for contrasting individual macromolecules involves the deposition of heavy metal vapor upon the specimen. We have investigated this process, and present here what we believe to be the more important considerations for optimizing it. Results of the application of these methods to several biological systems including muscle proteins, fibrinogen, ribosomes and chromatin will be discussed.

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Preparation of graft copolymers by the reaction of polymeric acyl chlorides with monohydroxy-terminated polymers: An introductory study

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19881735 ◽

1988 ◽

Vol 53 (8) ◽

pp. 1735-1744 ◽

Cited By ~ 1

Author(s):

Jitka Horská ◽

Jaroslav Stejskal ◽

Pavel Kratochvíl ◽

Aubrey D. Jenkins ◽

Eugenia Tsartolia ◽

...

Keyword(s):

Light Scattering ◽

Chemical Composition ◽

Statistical Model ◽

Graft Copolymers ◽

Coupling Reaction ◽

Molecular Characteristics ◽

Gel Formation ◽

Acyl Chlorides ◽

Molecular Weights

An attempt was made to prepare well-defined graft copolymers by the coupling reaction between acyl chloride groups located along the backbone chain and monohydroxy-terminated grafts prepared separately. The molecular weights and the parameters of heterogeneity in chemical composition of the products were determined by light scattering and osmometry. The determination of molecular characteristics revealed that the degree of grafting was low. The results therefore could not be confronted with a statistical model at this stage. The problems encountered in the synthesis, e.g., gel formation, and the data relating to the soluble products are discussed.

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Determination of pituitary and recombinant human growth hormone molecular weights by modern high-performance liquid chromatography with low angle laser light scattering detection

Journal of Chromatography A ◽

10.1016/s0021-9673(01)95363-4 ◽

1991 ◽

Vol 539 (1) ◽

pp. 91-109 ◽

Cited By ~ 16

Author(s):

Hans H. Stuting ◽

Ira S. Krull

Keyword(s):

Growth Hormone ◽

High Performance Liquid Chromatography ◽

High Performance ◽

Laser Light ◽

Recombinant Human Growth Hormone ◽

Human Growth ◽

Laser Light Scattering ◽

Molecular Weights ◽

Light Scattering Detection

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OSMOTIC PRESSURE STUDY OF PROTEIN FRACTIONS IN NORMAL AND IN NEPHROTIC SUBJECTS

Journal of Experimental Medicine ◽

10.1084/jem.69.6.819 ◽

1939 ◽

Vol 69 (6) ◽

pp. 819-831 ◽

Cited By ~ 11

Author(s):

Jaques Bourdillon

Keyword(s):

Osmotic Pressure ◽

Normal Serum ◽

The Other ◽

Protein Fractions ◽

Molecular Weights ◽

Other Hand ◽

Normal Albumin

In serum of patients with nephrosis both albumin and globulin showed by osmotic pressure nearly double the molecular weights of normal albumin and globulin. In the urines of such patients, on the other hand, both proteins showed molecular weights lower even than in normal serum. The colloidal osmotic pressures were measured by the author's method at such dilutions that the van't Hoff law relating pressures to molecular concentrations could be directly applied. For the albumin and globulin of normal serum the molecular weights found were 72,000 and 164,000 respectively, in agreement with the weights obtained by other methods.

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