scholarly journals The Proteins of the Keratin Component of Bird?s Beaks

1976 ◽  
Vol 29 (6) ◽  
pp. 467 ◽  
Author(s):  
MJ Frenkel ◽  
JM Gillespie
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Major Protein ◽  
Major Fraction ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Isoelectric Points ◽  
Related Proteins ◽  
Keratin Proteins ◽  
Similar Amino Acid

Birds' beaks have an outer shell of hard keratin which consists almost entirely of proteins which are very rich in glycine [about 30 residues per 100 residues (residues %)], contain moderate levels of tyrosine and serine (each about 8 residues %), and which have relatively low contents of cystine (about 2�5 residues %), lysine, histidine, isoleucine and methionine. Major protein fractions in the S-carboxymethyl form isolated from the beaks of 'six different orders of birds have similar amino acid compositions, isoelectric points (pH 4�2-4�9) and molecular weights (13 000--14 500). Detailed chromatographic electrophoretic and compositional studies of the proteins of kookaburra beak reveal them to be a family of closely related proteins with only limited heterogeneity, in contrast to mammalian keratin systems. The major kookaburra beak fraction is similar in overall composition and molecular weight to fowl epidermal scale, kookaburra claw and turtle scute proteins and shows some resemblance to reptile claw protein. Beaks also contain small amounts of protein which are distinctly different from the major fraction but which resemble feather keratin proteins in composition and size.

scholarly journals A comparison of the physical and chemical properties of four cytochromes c from Azotobacter vinelandii

1973 ◽  
Vol 135 (4) ◽  
pp. 617-630 ◽  
Author(s):  
Wilbur H. Campbell ◽  
William H. Orme-Johnson ◽  
Robert H. Burris
Keyword(s):  
Amino Acid ◽  
Spectral Properties ◽  
Azotobacter Vinelandii ◽  
Chemical Properties ◽  
Protein Cleavage ◽  
Separation And Purification ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Cytochromes C ◽  
Isoelectric Points

1. A modified method for the separation and purification of four cytochromes c from Azotobacter vinelandii is described. Two new cytochromes c have been purified and are designated cytochromes c(551) and c(555). 2. Additional evidence is presented to establish the dihaem nature of cytochrome c4. Ultracentrifugation data indicated similar molecular weights for the native and the denatured protein. Cleavage with CNBr yielded seven peptides; the amino acid compositions of the purified peptides were determined. Only one haem peptide was recovered. 3. Cytochromes c(551) and c(555) were characterized as acidic proteins of molecular weights about 12000. The spectral properties, isoelectric points, ‘maps’ of peptides from CNBr cleavage and amino acid compositions were determined for these two proteins. 4. The spectral properties, isoelectric points, molecular weights, CNBr peptide ‘maps’, amino acid compositions, relative oxidation–reduction potentials and e.p.r. (electron-paramagnetic-resonance) spectra of the four cytochromes c were compared. Cytochrome c4 and cytochrome c(551) appear to be distinct proteins. The distinction between cytochromes c5 and c(555) was not as clear, and our data are inadequate to establish firmly that they are distinct proteins. 5. The dihaem nature of cytochrome c4 is evident in its e.p.r. spectrum. The e.p.r. spectra are similar to the spectra of mammalian cytochromes c.

A comparison of four sulfhydryl cathepsins (B, C, H, and L) from porcine spleen

1984 ◽  
Vol 62 (12) ◽  
pp. 1301-1308 ◽  
Author(s):  
K. R. Lynn ◽  
Rosalind S. Labow
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
Cathepsin L ◽  
Gel Filtration ◽  
Cathepsin C ◽  
Molecular Weights ◽  
Isoelectric Points ◽  
Dipeptidyl Aminopeptidase ◽  
Precise Assessment ◽  
Similar Amino Acid

Four sulfhydryl cathepsins, B, C (dipeptidyl aminopeptidase I), H, and L were isolated from porcine spleen. They are all glycoproteins of similar amino acid compositions, which are comparable with those of cathepsins B and H from other sources and so with papain. All four cathepsins exist in multiple charged forms: B, C, H, and L have isoelectric points in the range 4.3–5.4, 5.3 and 5.9, 5.2–5.7, and 7–8.7, respectively. The molecular weights of cathepsins B and H were 24 000 and 26 000. Anomalous behaviour of cathepsin L on both conventional gel filtration and high pressure liquid chromatography precluded a precise assessment of its weight which is between 22 000 and 28 000. The isolated mercurial derivative of cathepsin C has a molecular weight of 56 000 (an active dimer formed on reduction). Cathepsins B and H also aggregate.

scholarly journals The purification and properties of the l-serine O-sulphate-degrading system of pig liver

1971 ◽  
Vol 121 (5) ◽  
pp. 747-752 ◽  
Author(s):  
N. Tudball ◽  
P. Thomas ◽  
R. Bailey-Wood
Keyword(s):  
Amino Acid ◽  
Isoelectric Focusing ◽  
Enzyme System ◽  
Gel Filtration ◽  
Pig Liver ◽  
Molecular Weights ◽  
Purification And Properties ◽  
Isoelectric Points ◽  
Degrading System ◽  
Similar Amino Acid

1. The enzyme system from pig liver responsible for the αβ-elimination of l-serine O-sulphate was purified 1000-fold. 2. Isoelectric focusing produced two enzymically active fractions with isoelectric points at pH5.6 and 5.9 respectively. 3. Osmometry and gel filtration showed both enzymes to possess molecular weights of approx. 54000. 4. The separate activities exhibited similar amino acid compositions.

scholarly journals THE PURIFICATION AND PARTIAL CHARACTERIZATION OF SEVERAL FORMS OF HOG RENIN SUBSTRATE

1963 ◽  
Vol 118 (1) ◽  
pp. 73-98 ◽  
Author(s):  
Leonard T. Skeggs ◽  
Kenneth E. Lentz ◽  
Harry Hochstrasser ◽  
Joseph R. Kahn
Keyword(s):  
Sialic Acid ◽  
Amino Acid ◽  
Physical Properties ◽  
Deae Cellulose ◽  
Angiotensin I ◽  
Renin Substrate ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Similar Amino Acid

Hog renin substrate has been separated into three major (A, B, and C) and two minor forms (D and E) by DEAE cellulose chromatography. Two of the major forms (B and C) have been further fractionated into two additional types (1 and 2) by countercurrent distribution. The purification of substrates A, C1, and C2 has been completed. Analysis shows that all three are glycoproteins with molecular weights of about 57,000, and have similar amino acid compositions. Differences exist in the sialic acid, glucosamine, and neutral hexose content, which may account for different physical properties. All the forms of the substrates are attacked by renin at similar rates, and appear to yield the same angiotensin I.

scholarly journals Comparison of Some Microfibrillar Proteins From Wool

1979 ◽  
Vol 32 (5) ◽  
pp. 437 ◽  
Author(s):  
Lyndsay M Dowling ◽  
Keith H Gough ◽  
Adam S Inglis ◽  
Lindsay G Sparrow
Keyword(s):  
Amino Acid ◽  
Sequence Homology ◽  
Amino Acid Sequences ◽  
Molecular Properties ◽  
Amino Acid Compositions ◽  
Molecular Weights ◽  
Sequence Homologies ◽  
Sulfur Protein ◽  
Low Sulfur ◽  
Similar Amino Acid

The molecular properties of components 5 and 7c, two low-sulfur proteins from the microfibril of wool, have been compared. These proteins have almost identical molecular weights and very similar amino acid compositions. Comparison of the partial amino acid sequences determined to date show extensive regions of sequence homology. No such sequence homologies are observed when these components are compared with component 8c-1, another low-sulfur protein from wool.

Effect of extractant and molecular size on the optical and chemical properties of soil humic acids

Soil Research ◽  
1969 ◽  
Vol 7 (3) ◽  
pp. 229 ◽  
Author(s):  
JHA Butler ◽  
JN Ladd
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Humic Acids ◽  
Gel Filtration ◽  
Chemical Properties ◽  
Molecular Size ◽  
Carboxyl Content ◽  
Peptide Bonds ◽  
Molecular Weights ◽  
Amino Acid Contents

Humic acids extracted from soil with sodium pyrophosphate have greater proportions of lower molecular weight material, less acid-hydrolysable amino acid nitrogen contents, but greater carboxyl contents and extinction values (260 and 450 nm) than humic acids extracted subsequently from the same sample with alkali. Humic acids extracted with alkali from fresh soil samples have intermediate values. Extinction values at 260 nm are directly correlated with carboxyl contents for a given soil. Different crop histories have no significant effect on the measured properties of the extracted humic acids. An alkali-extracted humic acid has been fractionated by gel filtration into seven fractions of different nominal molecular weight ranges. As the molecular weights of the fractions increase, both aliphatic C-H (based on infrared absorption at 2900 cm-1) and acid-hydrolysable amino acid contents increase, whereas extinction values at 260 nm and carboxyl contents decrease. The infrared spectra of the high molecular weight fractions have peaks at 1650 and 1510 cm-1 which correlate with acid-hydrolysable amino acid contents and which correspond to amide I and II bands of peptide bonds. Alkaline hydrolysis to split peptide bonds eliminates both these peaks. The spectra also have peaks at 1720 and 1210 cm-1 which correlate with the carboxyl content.

scholarly journals α-Crystallin. The isolation and characterization of distinct macromolecular fractions

1971 ◽  
Vol 124 (2) ◽  
pp. 337-343 ◽  
Author(s):  
Abraham Spector ◽  
Lu-Ku Li ◽  
Robert C. Augusteyn ◽  
Arthur Schneider ◽  
Thomas Freund
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Chemical Difference ◽  
Molecular Weights ◽  
Isolation And Characterization ◽  
Different Populations ◽  
Molecular Weight Fractions

α-Crystallin was isolated from calf lens periphery by chromatography on DEAE-cellulose and gel filtration. Three distinct populations of macromolecules have been isolated with molecular weights in the ranges approx. 6×105−9×105, 0.9×106−4×106and greater than 10×106. The concentration of macromolecules at the molecular-weight limits of a population are very low. The members of the different populations do not appear to be in equilibrium with each other. Further, in those molecular-weight fractions investigated, no equilibrium between members of the same population was observed. The population of lowest molecular weight comprises 65–75% of the total material. The amino acid and subunit composition of the different-sized fractions appear very similar, if not identical. The only chemical difference observed between the fractions is the presence of significant amounts of sugar in the higher-molecular-weight fractions. Subunit molecular weights of approx. 19.5×103and 22.5×103were observed for all α-crystallin fractions.

The outer membrane of Haemophilus influenzae type b: cell envelope associations of major proteins

1983 ◽  
Vol 29 (2) ◽  
pp. 280-287 ◽  
Author(s):  
J. W. Coulton ◽  
D. T. F. Wan
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulphate ◽  
Cell Envelope ◽  
Sodium Dodecyl ◽  
Haemophilus Influenzae Type ◽  
Major Protein ◽  
Haemophilus Influenzae Type B ◽  
Type B ◽  
Molecular Weights ◽  
Triton X

Membrane proteins fom the cell envelope of Haemophilus influenzae type b ATCC 9795 were examined by sodium dodecyl sulphate – polyacrylamide gel electrophoresis. When envelopes were extracted with a phosphate-based buffer containing 2% Triton X-100, a major protein of molecular weight 43 000 was detected in fractions containing cytoplasmic membrane proteins. The cell wall material which was Triton X-100 insoluble contained six major proteins of molecular weights 46 000, 40 000, 36 000, 30 000, 27 000, and 16 000. One of these proteins showed a shift in molecular weight from 27 000 to 36 000 when it was heated over a temperature range from 50 °C to 100 °C in buffer containing 2% sodium dodecyl sulphate, 5% 2-mercaptoethanol. This alteration in mobility could be demonstrated either by the membrane-bound form of the protein or by a detergent-soluble form of the protein. Enriched preparations of the 36 000 molecular weight form were obtained by a series of purification steps. Extraction of the Triton X-100 insoluble material with buffer containing 2% Triton X-100, 5.0 mM EDTA yielded chiefly one major protein molecular weight 30 000 and many minor protein species. Pretreatment of the Triton X-100 insoluble fraction with lysozyme followed by extraction with buffer containing 2% Triton X-100, 5.0 mM EDTA released two proteins of molecular weights 16 000 and 27 000 and few minor proteins. By these operational manipulations, the proteins of molecular weights 16 000 and 27 000 may be considered as peptidoglycan-associated proteins.

scholarly journals Homologies in amino acid composition and structure of histone F2al isolated from human leukaemic cells

1970 ◽  
Vol 119 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Laxman S. Desai ◽  
George E. Foley
Keyword(s):  
Gene Regulation ◽  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Neoplastic Cells ◽  
Amino Acid Compositions ◽  
Composition And Structure ◽  
Leukaemic Cells ◽  
Rf Values ◽  
Similar Amino Acid

Histones F2al extracted from normal and neoplastic cells possess similar amino acid compositions. Tryptic and chymotryptic peptides of the F2al histones have identical chromato-electrophoretic RF values. It is concluded that histones F2al from various sources have similar overall structures. The observed differences in the ratios of ∈-N-monomethyl- and di-∈-N-methyl-lysine in the histones from normal and neoplastic cells may be of significance with respect to gene regulation.

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