Structure of β-casein

SUMMARYThe temperature and concentration dependent association of β-casein was studied by means of viscometry, gel filtration chromatography, electron microscopy, analytical ultracentrifugation and UV difference spectrophotometry. Degrees of polymerization of 12, 22 and 49 and free energies of association of –21, –23 and – 25 kJ/mole monomer were found at temperatures of 10, 15 and 20 °C respectively in 0·2 M Na phosphate buffer pH 6·7.Monomeric β-casein was not a completely random coil but became more compact with increasing temperature, due to hydrophobic interactions.

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Location of an epitopic site on epiglycanin by molecular immunoelectron microscopy

Biochemical Journal ◽

10.1042/bj2270231 ◽

1985 ◽

Vol 227 (1) ◽

pp. 231-237 ◽

Cited By ~ 2

Author(s):

J K Wold ◽

H S Slayter ◽

J F Codington ◽

R W Jeanloz

Keyword(s):

Electron Microscopy ◽

Ion Exchange ◽

Immunoelectron Microscopy ◽

Gel Filtration ◽

Strong Tendency ◽

Gel Filtration Chromatography ◽

Shadow Casting ◽

Probable Presence ◽

Antigen Antibody

Antibodies of the IgM type present in rabbit anti-epiglycanin antiserum were purified by (NH4)2SO4 precipitation and by ion-exchange, affinity and gel-filtration chromatography. After papain treatment of this fraction, followed by gel filtration, the fraction with highest apparent Mr was incubated with epiglycanin, and the antigen-antibody complexes separated by gel filtration. These were examined by electron microscopy, using rotational shadow casting, and the photographs of the complexes were mapped for the locations of the antibody molecules on the extended epiglycanin molecules. Distribution of the frequency of attachment of immunoglobulin showed a strong tendency toward binding at one end of epiglycanin, suggesting the probable presence of only one epitope, probably a glycopeptide structure containing a beta-D-galactopyranosyl-(1→3)-2-acetamido-2-deoxy-D-galactose chain.

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Measurement of protein-protein association equilibria by large zone analytical gel filtration chromatography and equilibrium analytical ultracentrifugation

Advances in Biophysical Chemistry ◽

10.1016/s1057-8943(96)80008-3 ◽

1996 ◽

pp. 233-262

Author(s):

Dorothy Beckett ◽

Elizabeth Nenortas

Keyword(s):

Analytical Ultracentrifugation ◽

Gel Filtration ◽

Gel Filtration Chromatography ◽

Protein Association ◽

Association Equilibria

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Spontaneous Cataract in Nude Athymic Mice

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079991 ◽

1977 ◽

Vol 35 ◽

pp. 512-513

Author(s):

Ronald H. Bradley ◽

R. S. Berk ◽

L. D. Hazlett

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Nude Mouse ◽

Cellular Immunity ◽

Phosphate Buffer ◽

Osmium Tetroxide ◽

Athymic Mice ◽

Transmission Microscopy ◽

Mouse Lens ◽

Scanning Electron

The nude mouse is a hairless mutant (homozygous for the mutation nude, nu/nu), which is born lacking a thymus and possesses a severe defect in cellular immunity. Spontaneous unilateral cataractous lesions were noted (during ocular examination using a stereomicroscope at 40X) in 14 of a series of 60 animals (20%). This transmission and scanning microscopic study characterizes the morphology of this cataract and contrasts these data with normal nude mouse lens.All animals were sacrificed by an ether overdose. Eyes were enucleated and immersed in a mixed fixative (1% osmium tetroxide and 6% glutaraldehyde in Sorenson's phosphate buffer pH 7.4 at 0-4°C) for 3 hours, dehydrated in graded ethanols and embedded in Epon-Araldite for transmission microscopy. Specimens for scanning electron microscopy were fixed similarly, dehydrated in graded ethanols, then to graded changes of Freon 113 and ethanol to 100% Freon 113 and critically point dried in a Bomar critical point dryer using Freon 13 as the transition fluid.

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Binucleate Spermiogenesis in the Mouse

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010009381x ◽

1972 ◽

Vol 30 ◽

pp. 112-113

Author(s):

John J. Wolosewick

Keyword(s):

Electron Microscopy ◽

Phosphate Buffer ◽

Seminiferous Epithelium ◽

Mouse Testis ◽

Germinal Epithelium ◽

Intercellular Bridges ◽

Adult Mice ◽

Cervical Dislocation ◽

Human And Mouse

Classically, the male germinal epithelium is depicted as synchronously developing uninucleate spermatids conjoined by intercellular bridges. Recently, binucleate and multinucleate spermatids from human and mouse testis have been reported. The present paper describes certain developmental events in one type of binucleate spermatid in the seminiferous epithelium of the mouse.Testes of adult mice (ABP Jax) were removed from the animals after cervical dislocation and placed into 2.5% glutaraldehyde/Millonig's phosphate buffer (pH 7.2). Testicular capsules were gently split and separated, exposing the tubules. After 15 minutes the tissue was carefully cut into cubes (approx. 1mm), fixed for an additional 45 minutes and processed for electron microscopy.

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Turbomolecular Pumped Electron Microscopy of Rubella Virus (In BHK Celis)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100767 ◽

1968 ◽

Vol 26 ◽

pp. 204-205

Author(s):

A. B. Taylor ◽

G. C. Cole ◽

M. A. Holcomb ◽

C. A. Baechler

Keyword(s):

Electron Microscopy ◽

Rubella Virus ◽

Phosphate Buffer ◽

Fetal Calf Serum ◽

Calf Serum ◽

Basal Medium ◽

Kidney Cells ◽

Baby Hamster Kidney ◽

Input Multiplicity ◽

Baby Hamster Kidney Cells

An aliquot from a continuous fermenter culture of baby hamster kidney cells (BHK-21 Clone PD-4) (Wistar) maintained in Ca free Eagle's Basal Medium containing 2% Kaolin adsorbed fetal calf serum was planted in spinner flasks at 300,000 cells per ml, total volume 600 ml. After equilibration for one day at 35°C to insure that cells were in log phase, the culture was infected with the M-33-AGMK25 BHK-219 strain of rubella at an input multiplicity of about 6 TCID50 per cell. The virus was identified with specific rubella antiserum.Preliminary experiments had shown that such cultures would reach a peak or plateau HA titer of approximately 1:64, 24 hrs after inoculation and would continue to yield virus for 6 to 12 days. One hundred ml aliquot harvests were withdrawn daily and the culture was returned to volume with growth medium and incubation continued. The harvested cells were spun down rapidly at 2500 rpm per 15 mins., fixed in 3.7% gluteraldehyde in Ca free phosphate buffer saline, and post fixed in osmium tetraoxide. After dehydration, the cells were embedded in Epon 812 and cured approximately 20 hrs at 60°C.

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Quantitative determination of the beta-2-microglobulin monomer by gel filtration chromatography

Chinese Journal of Chromatography ◽

10.3724/sp.j.1123.2018.11028 ◽

2019 ◽

Vol 37 (5) ◽

pp. 533

Author(s):

Xiaobo BAO ◽

Jun REN ◽

Yufeng WANG ◽

Lingyun JIA

Keyword(s):

Quantitative Determination ◽

Gel Filtration ◽

Gel Filtration Chromatography ◽

Beta 2 ◽

Beta 2 Microglobulin

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Terpene polyacrylate TPA5 shows favorable molecular hydrodynamic properties as a potential bioinspired archaeological wood consolidant

Scientific Reports ◽

10.1038/s41598-021-86543-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Michelle Cutajar ◽

Fabrizio Andriulo ◽

Megan R. Thomsett ◽

Jonathan C. Moore ◽

Benoit Couturaud ◽

...

Keyword(s):

Molar Mass ◽

Analytical Ultracentrifugation ◽

Gel Filtration ◽

Axial Ratio ◽

Sedimentation Equilibrium ◽

Archaeological Wood ◽

Molecular Hydrodynamic ◽

Pine Trees ◽

Minimal Concentration ◽

Hydrogen Bonding Potential

AbstractThere is currently a pressing need for the development of novel bioinspired consolidants for waterlogged, archaeological wood. Bioinspired materials possess many advantages, such as biocompatibility and sustainability, which makes them ideal to use in this capacity. Based on this, a polyhydroxylated monomer was synthesised from α-pinene, a sustainable terpene feedstock derived from pine trees, and used to prepare a low molar mass polymer TPA5 through free radical polymerisation. This polymer was extensively characterised by NMR spectroscopy (chemical composition) and molecular hydrodynamics, primarily using analytical ultracentrifugation reinforced by gel filtration chromatography and viscometry, in order to investigate whether it would be suitable for wood consolidation purposes. Sedimentation equilibrium indicated a weight average molar mass Mw of (4.3 ± 0.2) kDa, with minimal concentration dependence. Further analysis with MULTISIG revealed a broad distribution of molar masses and this heterogeneity was further confirmed by sedimentation velocity. Conformation analyses with the Perrin P and viscosity increment ν universal hydrodynamic parameters indicated that the polymer had an elongated shape, with both factors giving consistent results and a consensus axial ratio of ~ 4.5. These collective properties—hydrogen bonding potential enhanced by an elongated shape, together with a small injectable molar mass—suggest this polymer is worthy of further consideration as a potential consolidant.

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