scholarly journals Characterization of calcium-dependent membrane binding proteins of brain cortex

1985 ◽  
Vol 229 (3) ◽  
pp. 587-593 ◽  
Author(s):  
A R Rhoads ◽  
M Lulla ◽  
P B Moore ◽  
C E Jackson
Keyword(s):  
Brain Cortex ◽  
Peptide Mapping ◽  
Bovine Brain ◽  
Particulate Fraction ◽  
Structural Homology ◽  
One Dimensional ◽  
Calcium Dependent ◽  
Stokes Radius ◽  
The Brain

Proteins of Mr 68 000, 34 000 and 32 000 were selectively extracted by EGTA from brain cortex. The three proteins that were extracted along with calmodulin were acidic, monomeric, and did not exhibit structural homology, as demonstrated by one-dimensional peptide mapping. The Mr-68 000 protein was purified to homogeneity and had a Stokes radius of 3.54 nm and S20,W value of 5.1S. Purified calmodulin, Mr-68 000 protein and two proteins of Mr 34 000 and Mr 32 000, interacted with the brain particulate fraction, with half-maximal binding occurring at 3.5 microM, 8.3 microM and 150 microM-Ca2+ respectively. Proteins were bound independently of each other and calmodulin. Pretreatment of the particulate fraction with trypsin prevented the Ca2+-dependent binding of calmodulin; however, the binding of the Mr-68 000 protein or the Mr−32 000 and −34 000 proteins was unaffected. The Mr-68 000 protein of bovine brain did not cross-react immunologically with Mr-67 000 calcimedin from chicken gizzard.

scholarly journals Dynamic ionic radius of alkali metal ions in aqueous solution: a pulsed-field gradient NMR study

RSC Advances ◽  
2021 ◽  
Vol 11 (33) ◽  
pp. 20252-20257
Author(s):  
Kikuko Hayamizu ◽  
Yusuke Chiba ◽  
Tomoyuki Haishi
Keyword(s):  
Aqueous Solution ◽  
Alkali Metal ◽  
Metal Ions ◽  
Field Gradient ◽  
Ionic Radius ◽  
Alkali Metal Ions ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Nmr Study ◽  
Stokes Radius

Stokes radius (dynamic ionic radius) of the alkali metal ions versus the ionic radius (Rion) at 303 K. The dotted line is a guide for the 1 : 1 relation.

scholarly journals Cytosol oestrogen receptor of lactating mammary gland. Effect of heparin on the aggregation of the receptor and interaction of the receptor with heparin-Sepharose

1978 ◽  
Vol 171 (1) ◽  
pp. 137-141 ◽  
Author(s):  
F Auricchio ◽  
A Rotondi ◽  
P Sampaolo ◽  
E Schiavone
Keyword(s):  
Mammary Gland ◽  
Oestrogen Receptor ◽  
High Speed ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Sedimentation Coefficient ◽  
Large Aggregate ◽  
Low Salt ◽  
Lactating Mammary Gland ◽  
Stokes Radius

1. An oestrogen receptor is present in low-salt cytosol of the mammary gland of lactating mice as a large aggregate; it is excluded from gel matrix when filtered on a Sephadex G-200 column and sediments at 7S in sucrose gradients. After incubation of cytosol with heparin, the receptor is dissociated. On a Sephadex G-200 column, it is included in the gel matrix and eluted as a protein with mol.wt. 260000 and a Stokes radius of 6.8nm; it sediments at 6S in sucrose gradients. 2. Dissociation of the mammary-gland cytosol oestrogen receptor seems to be the result of interaction of the oestrogen-receptor complex with heparin. This receptor interacts with heparin covalently bound to Sepharose, thereafter sedimenting at 6S. By using this interaction, the cytosol receptor was purified 200-fold compared with the homogenate, with a yield of 70%. 3. The cytosol receptor that was not incubated or was incubated with heparin was much smaller during sucrose-gradient centrifugation than during gel filtration. This discrepancy can be explained by pressure-induced dissociation during high-speed centrifugation. This possibility is supported by the decrease in the sedimentation coefficient of the receptor with increased duration of centrifugation.

scholarly journals Domain structure and functional analysis of the carboxyl-terminal polyacidic sequence of the RAD6 protein of Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (3) ◽  
pp. 1179-1185 ◽  
Author(s):  
A Morrison ◽  
E J Miller ◽  
L Prakash
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Proteinase K ◽  
Intrinsic Activity ◽  
Structural Domain ◽  
Globular Domain ◽  
Wild Type ◽  
Calculated Mass ◽  
Stokes Radius ◽  
Carboxyl Terminal

The RAD6 gene of Saccharomyces cerevisiae, which is required for normal tolerance of DNA damage and for sporulation, encodes a 172-residue protein whose 23 carboxyl-terminal residues are almost all acidic. We show that this polyacidic sequence appends to RAD6 protein as a polyanionic tail and that its function in vivo does not require stoichiometry of length. RAD6 protein was purified to near homogeneity from a yeast strain carrying a RAD6 overproducing plasmid. Approximately the first 150 residues of RAD6 protein composed a structural domain that was resistant to proteinase K and had a Stokes radius typical of a globular protein of its calculated mass. The carboxyl-terminal polyacidic sequence was sensitive to proteinase K, and it endowed RAD6 protein with an aberrantly large Stokes radius that indicates an asymmetric shape. We deduce that RAD6 protein is monomeric and comprises a globular domain with a freely extending polyacidic tail. We tested the phenotypic effects of partial or complete deletion of the polyacidic sequence, demonstrating the presence of the shortened proteins in the cell by using antibody to RAD6 protein. Removal of the entire polyacidic sequence severely reduced sporulation but only slightly affected survival after UV irradiation or UV-induced mutagenesis. Strains with deletions of all but the first 4 or 15 residues of the polyacidic sequence were phenotypically almost wild type or wild type, respectively. We conclude that the intrinsic activity of RAD6 protein resides in the globular domain, that the polyacidic sequence has a stimulatory or modifying role evident primarily in sporulation, and that only a short section apparently functions as effectively as the entire polyacidic sequence.

scholarly journals Structural mechanisms of acute VEGF effect on microvessel permeability

2003 ◽  
Vol 284 (6) ◽  
pp. H2124-H2135 ◽  
Author(s):  
Bingmei M. Fu ◽  
Shang Shen
Keyword(s):  
Structural Changes ◽  
Fold Increase ◽  
Sodium Fluorescein ◽  
Vascular Endothelial ◽  
Apparent Permeability ◽  
Stokes Radius ◽  
Microvessel Permeability ◽  
Structural Mechanisms ◽  
Endothelial Growth Factor ◽  
Small Solute

To investigate the ultrastructural mechanisms of acute microvessel hyperpermeability by vascular endothelial growth factor (VEGF), we combined a mathematical model ( J Biomech Eng 116: 502–513, 1994) with experimental data of the effect of VEGF on microvessel hydraulic conductivity ( L p) and permeability of various-sized solutes. We examined the effect of VEGF on microvessel permeability to a small solute (sodium fluorescein, Stokes radius 0.45 nm), an intermediate solute (α-lactalbumin, Stokes radius 2.01 nm), and a large solute [albumin (BSA), Stokes radius 3.5 nm]. Exposure to 1 nM VEGF transiently increased apparent permeability to 2.3, 3.3, and 6.2 times their baseline values for sodium fluorescein, α-lactalbumin, and BSA, respectively, within 30 s, and all returned to control within 2 min. On the basis of L p (DO Bates and FE Curry. Am J Physiol Heart Circ Physiol 271: H2520–H2528, 1996) and permeability data, the prediction from the model suggested that the most likely structural changes in the interendothelial cleft induced by VEGF would be a ∼2.5-fold increase in its opening width and partial degradation of the surface glycocalyx.

scholarly journals PURIFICATION AND PHYSICAL PROPERTIES OF GROUP C STREPTOCOCCAL PHAGE-ASSOCIATED LYSIN

1971 ◽  
Vol 133 (5) ◽  
pp. 1105-1117 ◽  
Author(s):  
Vincent A. Fischetti ◽  
Emil C. Gotschlich ◽  
Alan W. Bernheimer
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Physical Properties ◽  
Total Protein ◽  
Sedimentation Coefficient ◽  
Polyacrylamide Gel ◽  
Single Band ◽  
Purification Procedure ◽  
Sh Group ◽  
Stokes Radius

A purification procedure for the Group C phage-associated lysin is described utilizing tetrathionate to protect the enzyme's -SH group(s) from thiol-inactivating agents. A 652-fold purification has been accomplished yielding a solution in which the enzyme activity corresponds to essentially a single band on polyacrylamide gel which accounts for 70% of the total protein in the preparation. A molecular weight of 101,000 and frictional ratio of 1.526 was determined for the lysin utilizing experimentally determined values for its Stokes radius and sedimentation coefficient.

scholarly journals Purification of a cortical complex containing two unconventional actins from Acanthamoeba by affinity chromatography on profilin-agarose.

1994 ◽  
Vol 127 (1) ◽  
pp. 107-115 ◽  
Author(s):  
L M Machesky ◽  
S J Atkinson ◽  
C Ampe ◽  
J Vandekerckhove ◽  
T D Pollard
Keyword(s):  
Gel Filtration ◽  
Protein Sequences ◽  
Rabbit Muscle ◽  
Muscle Actin ◽  
Novel Proteins ◽  
Cell Extracts ◽  
A Value ◽  
Stokes Radius ◽  
Globular Particle ◽  
Stoichiometric Complex

We identified four polypeptides of 47, 44, 40, and 35 kD that bind to profilin-Sepharose and elute with high salt. When purified by conventional chromatography using an antibody to the 47-kD polypeptide, these four polypeptides copurified as a stoichiometric complex together with three additional polypeptides of 19, 18, and 13 kD that varied in their proportions to the other polypeptides. Partial protein sequences showed that the 47-kD polypeptide is a homologue of S. pombe act2 and the 44-kD polypeptide is a homologue of S. cerevisiae ACT2, both unconventional actins. The 40-kD polypeptide contains a sequence similar to the WD40 motif of the G beta subunit of a trimeric G-protein from Dictyostelium discoideum. From partial sequences, the 35-, 19-, and 18-kD polypeptides appear to be novel proteins. On gel filtration the complex of purified polypeptides cochromatograph with a Stokes' radius of 4.8 nm, a value consistent with a globular particle of 220 kD containing one copy of each polypeptide. Cell extracts also contain components of the complex that do not bind the profilin column. Affinity purified antibodies localize 47- and 18/19-kD polypeptides in the cortex and filopodia of Acanthamoeba. Antibodies to the 47-kD unconventional actin cross-react on immunoblots with polypeptides of similar size in Dictyostelium, rabbit muscle, and conventional preparations of rabbit muscle actin but do not react with actin.

Purification of factor EF-P, a protein that stimulates peptide-bond synthesis with certain aminoacyl-tRNA analogues

1979 ◽  
Vol 57 (6) ◽  
pp. 749-757 ◽  
Author(s):  
Bernard R. Glick ◽  
Robert M. Green ◽  
M. Clelia Ganoza
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Protein Biosynthesis ◽  
Bond Formation ◽  
Frictional Coefficient ◽  
Peptide Bond ◽  
Asymmetric Structure ◽  
Peptide Bond Formation ◽  
Apparent Homogeneity ◽  
Stokes Radius

Factor EF-P is a nonribosomal (soluble) protein of Escherichia coli that stimulates peptide bond synthesis when certain aminoacyl-tRNA analogues are used. The purification of this protein to apparent homogeneity is described here. EF-P has a molecular weight of about 21 000, a Stokes radius of 27 Å (1 Å = 0.1 nm), and a frictional coefficient of 1.48, suggesting an asymmetric structure. By this and a number of other criteria, EF-P is a new factor that controls peptide bond formation during protein biosynthesis.

scholarly journals Purification and some properties of rabbit antiovalbumin

1973 ◽  
Vol 135 (4) ◽  
pp. 705-711 ◽  
Author(s):  
Aftab A. Ansari ◽  
A. Salahuddin
Keyword(s):  
Molecular Weight ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Acid Media ◽  
Stokes Radius ◽  
Antigen Antibody ◽  
Two Peaks ◽  
Complete Dissociation ◽  
Phosphate Groups

Unlike previous reports that the ovalbumin–anti-ovalbumin complex did not dissociate completely in acid media, our results showed complete dissociation of the complex both in 1.2m-acetic acid, pH2.3, and in KCl–HCl, pH2.2, I 0.06. Thus Sephadex chromatography of the solution obtained by dissolving the antigen–antibody precipitate in these media repeatedly gave two peaks corresponding to anti-ovalbumin and ovalbumin. Further, gel-diffusion and immunoelectrophoresis experiments showed that the phosphate groups of ovalbumin are not involved in the antigenic sites. The antibody thus purified was more easily precipitated than previous preparations. The molecular weight and Stokes radius of the antibody were calculated from its gel-filtration behaviour and were found to be 148000 and 4.8nm respectively. The molecular weight determined by sodium dodecyl sulphate–polyacrylamide gel electrophoresis was essentially similar (about 0.7% lower).

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