scholarly journals Galactothermin, a reversibly heat-precipitable protein of human milk at neutral pH

1970 ◽  
Vol 118 (1) ◽  
pp. 181-186 ◽  
Author(s):  
A. L. Schade ◽  
R. W. Reinhart
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Human Milk ◽  
Skim Milk ◽  
Sedimentation Coefficient ◽  
Amino Acid Residues ◽  
Isolation And Purification ◽  
Neutral Ph ◽  
Polar Species ◽  
Ultracentrifugal Analysis

1. A protein, aggregating at body temperature and solubilizing when cooled, was isolated from fresh human milk at neutral pH and studied for some of its physical, chemical and immunological properties. The name `galactothermin' is proposed for this protein. 2. Isolation and purification of galactothermin involved casein removal from skim milk at pH4.64 followed by centrifugal fractionation of residual protein-containing solutions repeatedly heated and cooled between 40°C and 0°C at pH7.3. 3. The molecular weight by ultracentrifugal analysis and the minimum molecular weight by sum of amino acid residues were 11400 and 14000 respectively. The sedimentation coefficient s25,w was 1.05S and the diffusion coefficient was 7.15×10−7. Reversible aggregation is favoured by increase in protein concentration, ionic strength, temperature, time and approach to the isoionic point of 7.27 from either acidic or alkaline conditions. 4. Among the amino acid residues, proline predominates and non-polar species account for two-thirds of the total. Cysteine and cystine are absent. Analysis of galactothermin showed it to be essentially free of hexose, sialic acid, calcium and phosphate. 5. Galactothermin is antigenic in the rabbit as evidenced by the passive cutaneous anaphylaxis test. Single precipitin lines are produced in immunodiffusion tests. 6. By electrophoresis in polyacrylamide gel at pH4.0 only one sharp band is produced.

The C-terminal sequence of amino acid residues of κ-casein isolated from buffalo's milk

1967 ◽  
Vol 34 (1) ◽  
pp. 85-88 ◽  
Author(s):  
M. H. Abd El-Salam ◽  
W. Manson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Peptide Chain ◽  
Amino Acid Residues ◽  
Terminal Sequence ◽  
Carboxypeptidase A ◽  
Phosphorous Content ◽  
Single Peptide

SummaryWhen κ-casein from buffalo's milk was treated with carboxypeptidase A (EC 3. 4. 2. 1),4 amino acids, valine, threonine, serine and alanine were released from the protein in a manner consistent with the view that they originate in the C-terminal sequence of a single peptide chain. The amounts produced suggest a minimum molecular weight for buffalo κ-casein of approximately 17000, in agreement with the value calculated from the phosphorous content on the basis of the presence of 2 phosphorus atoms/molecule. A comparison is made with the C-terminal sequence reported for bovine κ-casein.

scholarly journals Sea urchin (Anthocidaris crassispina) egg zinc-binding protein. Cellular localization, purification and characterization

1983 ◽  
Vol 211 (1) ◽  
pp. 109-118 ◽  
Author(s):  
H Ohtake ◽  
T Suyemitsu ◽  
M Koga
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Sea Urchin ◽  
Cellular Localization ◽  
Binding Protein ◽  
Gel Permeation Chromatography ◽  
Total Amino Acid ◽  
Amino Acid Residues ◽  
Gel Permeation ◽  
Anthocidaris Crassispina

Gel-filtration analysis of cytosol fraction obtained from unfertilized sea-urchin (Anthocidaris crassispina) eggs on Sephadex G-75 revealed the presence of two Zn-binding-protein fractions. The major Zn-binding protein fraction had a low molecular weight and a low absorbance at 280 nm, properties similar to those of the metallothionein found in the regenerating rat liver. These fractions were further purified by DEAE-cellulose and Sephadex G-50 chromatography. Homogeneity of the Zn-binding protein was judged by polyacrylamide-disc-gel electrophoresis and gel-permeation chromatography in the presence of 6 M-guanidinium chloride. The molecular weight determined by gel-permeation chromatography was 3900. This value is in good agreement with the minimum molecular weight calculated from the amino acid composition, which was 3655. Zn-binding protein is composed of 36 amino acid residues and the distinctive features include an extremely high content of cysteine, which accounted for one-third of the total amino acid residues, and a complete absence of aromatic amino acids, as well as of methionine, histidine and arginine. Zn-binding protein contained 4.1 g-atoms of zinc per mol and a trace of cadmium, but no copper, iron or calcium. The molar ratio of reactive thiol groups to metal ion was calculated to be 2.73:1. Possible roles of this Zn-binding protein in the homoeostasis of zinc in unfertilized sea-urchin eggs are discussed.

Studies on Chymotrypsin-P. I. Characterization

1971 ◽  
Vol 49 (9) ◽  
pp. 999-1004 ◽  
Author(s):  
M. C. Shaw ◽  
T. Viswanatha
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Physicochemical Properties ◽  
Gel Filtration ◽  
Amino Acid Residues ◽  
The Difference ◽  
Filtration Technique

The physicochemical properties of chymotrypsin-P obtained by the papain activation of chymotrypsinogen have been investigated. The molecular weight of this enzyme as determined by gel filtration technique has been found to be 24 000 ± 1000. The amino acid residues occupying the N-terminal positions and the composition of the B- and C-chains of chymotrypsin-P are identical with those found in α-chymotrypsin. Thus the difference between the two enzymes is restricted to the composition of their A-chains.

Isolation of Two Bovine Amelogenin Peptides and Their Amino Acid Sequences

1987 ◽  
Vol 1 (2) ◽  
pp. 276-281 ◽  
Author(s):  
J.-H. Yeh ◽  
T. Takagi ◽  
S. Sasaki
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Amino Acid Sequences ◽  
Polyacrylamide Gel ◽  
The Other ◽  
Edman Degradation ◽  
Amino Acid Residues ◽  
Peptide Fractions

Two peptide fractions of bovine amelogenin having a highly aggregative property to form polymers were purified by chromatography, SDS-polyacrylamide gel electrophoresis, and HPLC. Amino acid sequences of purified peptides were determined by automated Edman degradation. One peptide was found to be composed of 63 amino acid residues having a molecular weight of 7105, and the other of 86 residues having that of 9683. The sequence of the smaller peptide was identical to the C-terminal 63 residues of the amelogenin molecule of 170 residues previously reported, but the larger contained eight residues which are absent in the amelogenin sequence. There is a possibility that the latter peptide might be synthesized independently from mRNA spliced at different positions.

Purification and studies of some physicochemical properties of glutamine synthetase of Neurospora crassa

1978 ◽  
Vol 56 (10) ◽  
pp. 927-933 ◽  
Author(s):  
W. S. Lin ◽  
M. Kapoor
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Glutamine Synthetase ◽  
Neurospora Crassa ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Sedimentation Coefficient ◽  
Affinity Column ◽  
Subunit Structure ◽  
Α Helix

Glutamine synthetase (EC 6.3.1.2) of Neurospora crassa was purified to near homogeneity by chromatography on a glutamate–Sepharose affinity column. Its properties, including molecular weight, subunit structure, amino acid composition, and approximate α-helix content, have been examined. In the native state, this enzyme has been demonstrated by gel filtration to be an octamer of molecular weight 360 000 and as having a sedimentation coefficient of 13.2 S by sedimentation velocity measurements. Circular dichroism spectra in the far ultraviolet range suggest an approximate α-helix content of 23–24%. The subunit generated by treatment with urea was found to be 45 000 daltons by gel filtration methods and a molecular weight of 46 000 was calculated for the monomer obtained by sodium dodecyl sulphate (SDS) treatment and electrophoresis in SDS-polyacrylamide gels. Interprotomeric cross-linking experiments, using diimidoesters, suggest the presence of two noncovalently linked tetramers comprising the native octameric structure. Amino acid analyses revealed the presence of six tryptophans, four half cystines, and nine methionine residues per monomer of 45 000 daltons.

Purification and Characterization of Cytochrome 553 from the Chrysophycean Alga Monochrysis lutheri

1971 ◽  
Vol 49 (6) ◽  
pp. 641-646 ◽  
Author(s):  
M. V. Laycock ◽  
J. S. Craigie
Keyword(s):  
Amino Acid ◽  
Higher Plants ◽  
Sedimentation Coefficient ◽  
Cytochrome F ◽  
Reduced Form ◽  
Amino Acid Residues ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential ◽  
Equilibrium Centrifugation

Cytochrome 553, an electron carrier in photosynthesis and a functional analogue of cytochrome f of higher plants, was isolated from Monochrysis lutheri and purified by salt fractionation, chromatography, and isoelectric focussing. Absorption maxima occurred at 275, 320, 416, 523, and 553 nm in the reduced form. The α-absorption peak was symmetrical and had an extinction coefficient of 25.9 mM−1 cm−1. The molecular weight was 11 100 by equilibrium centrifugation, 12 400 from iron determinations, and 10 300 from the amino acid composition. The molecule consisted of one heme group and 91 amino acid residues including two cysteine residues and one each of histidine, arginine, tryptophan, methionine, and proline. Other physical properties measured were: the sedimentation coefficient, 1.3 S; the normal oxidation reduction potential, + 0.388 V; and the isoelectric point, pH 3.75.

Amino acid sequence of the acidic acrosin inhibitor (BUSI I B2) from bull seminal plasma

1983 ◽  
Vol 48 (9) ◽  
pp. 2558-2568 ◽  
Author(s):  
Bedřich Meloun ◽  
Věra Jonáková ◽  
Dana Čechová
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Seminal Plasma ◽  
Sequential Data ◽  
Amino Acid Residues

The molecule of the inhibitor consists of 63 amino acid residues whose sequence is the following: Glu-Ile-Tyr-Phe-Glu-Pro-Asp-Phe-Gly-Phe-Pro-Pro-Asp-Cys-Lys-Val-Tyr-Thr-Glu-Ala-Cys-Thr-Arg-Glu-Tyr-Asn-Pro-Ile-Cys-Asp-Ser-Ala-Ala-Lys-Thr-Tyr-Ser-Asn-Glu-Cys-Thr-Phe-Cys-Asn-Glu-Lys-Met-Asn-Asn-Asp-Ala-Asp-Ile-His-Phe-Gln-His-Phe-Gly-Glu-Cys-Glu-Tyr. The sequential data were obtained by the analysis of peptides isolated from the tryptic and chymotryptic digest of the carboxymethylated inhibitor. The molecular weight of the inhibitor calculated from its amino acid sequence is 7377.

PRP19: a novel spliceosomal component

1993 ◽  
Vol 13 (3) ◽  
pp. 1876-1882
Author(s):  
S C Cheng ◽  
W Y Tarn ◽  
T Y Tsao ◽  
J Abelson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Molecular Weight ◽  
Amino Acid ◽  
The Other ◽  
Splicing Factor ◽  
Growth Defect ◽  
Splicing Factors ◽  
Temperature Sensitive ◽  
Amino Acid Residues ◽  
Exact Function

We have isolated the gene of a splicing factor, PRP19, by complementation of the temperature-sensitive growth defect of the prp19 mutant of Saccharomyces cerevisiae. The gene encodes a protein of 502 amino acid residues of molecular weight 56,500, with no homology to sequences in the data base. Unlike other PRP proteins or mammalian splicing factors, the sequence of PRP19 has no discernible motif. Immunoprecipitation studies showed that PRP19 is associated with the spliceosome during the splicing reaction. Although the exact function of PRP19 remains unknown, PRP19 appears to be distinct from the other PRP proteins or other spliceosomal components.

Effect of peptide chain length on amino acid and nitrogen absorption from two lactalbumin hydrolysates in the normal human jejunum

1986 ◽  
Vol 71 (1) ◽  
pp. 65-69 ◽  
Author(s):  
G. K. Grimble ◽  
P. P. Keohane ◽  
B. E. Higgins ◽  
M. V. Kaminski ◽  
D. B. A. Silk
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Chain Length ◽  
Peptide Chain ◽  
Amino Acid Residues ◽  
Peptide Hydrolysis ◽  
Copper Chelation ◽  
A Chain ◽  
Jejunal Perfusion ◽  
Peptide Chain Length

1. A double lumen jejunal perfusion technique has been used in man to study the effect of peptide chain length on absorption of amino acid nitrogen from two partial enzymic hydrolysates of lactalbumin. 2. Copper-chelation chromatography showed that one lactalbumin hydrolysate (LH2) contained 98% peptides with a chain length > 4, whilst the other (LH1) contained a more even spread of chain lengths with 55% <4. 3. Absorption of total nitrogen and of 14 amino acid residues occurred to a significantly greater extent from the low molecular weight LH1 than from the higher molecular weight LH2. 4. The results suggest that the pattern of nitrogen and amino acid absorption from partial enzymic hydrolysates of whole protein is markedly influenced by peptide chain length and that brush border peptide hydrolysis has an important rate limiting effect on absorption rates.

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