Purification and Characterization of a Trypsin Inhibitor from Solanum tuberosum

1975 ◽  
Vol 53 (9) ◽  
pp. 958-974 ◽  
Author(s):  
Maurice Rouleau ◽  
François Lamy
Keyword(s):  
Amino Acid ◽  
Trypsin Inhibitor ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sedimentation Equilibrium ◽  
Acetone Powder ◽  
Amino Acid Residues ◽  
Single Polypeptide Chain ◽  
Physicochemical Methods ◽  
Single Polypeptide ◽  
Inhibition Experiment

A trypsin inhibitor isolated from a potato acetone powder has been purified by affinity chromatography. This protein inhibits trypsin mole per mole. To a lesser extent it combines also with chymotrypsin and elastase. For trypsin, Ki = 8 × 10−7 M. The inhibitor has a single polypeptide chain of 207 amino acid residues. It contains no sugar or free sulfhydryl groups. Its extinction coefficient E2801% = 10.3 and its isoelectric point is 6.9. Its molecular weight is of the order of 21 000–22 000, as determined by sedimentation equilibrium, by inhibition experiment or from its amino acid composition. These same techniques, taken together with the single band observed at different pH on polyacrylamide gel electrophoresis, indicate that the protein purified is monodisperse. However, the finding of two N-terminal amino acid residues, leucine and aspartic acid, and the different stoichiometry observed during the interaction of the inhibitor, either with trypsin or with chymotrypsin and elastase, raises the possibility that our preparation is contaminated by a polyvalent inhibitor not detectable by physicochemical methods.

The power of the force: mechano-physiology of the giant titin

2018 ◽  
Vol 2 (5) ◽  
pp. 681-686 ◽  
Author(s):  
Jaime Andrés Rivas-Pardo
Keyword(s):  
Amino Acid ◽  
Human Body ◽  
Actin Filaments ◽  
Polypeptide Chain ◽  
Single Gene ◽  
The Other ◽  
Amino Acid Residues ◽  
The Third ◽  
Single Polypeptide Chain ◽  
Single Polypeptide

Titin — the largest protein in the human body — spans half of the muscle sarcomere from the Z-disk to the M-band through a single polypeptide chain. More than 30 000 amino acid residues coded from a single gene (TTN, in humans Q8WZ42) form a long filamentous protein organized in individual globular domains concatenated in tandem. Owing to its location and close interaction with the other muscle filaments, titin is considered the third filament of muscle, after the thick-myosin and the thin-actin filaments.

scholarly journals The amino acid sequence of plastocyanin from Cucurbita pepo L. (vegetable marrow)

1974 ◽  
Vol 143 (2) ◽  
pp. 257-264 ◽  
Author(s):  
Michael D. Scawen ◽  
Donald Boulter
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Phenyl Isothiocyanate ◽  
Amino Acid Residues ◽  
Higher Plant ◽  
Single Polypeptide Chain ◽  
Vegetable Marrow ◽  
Single Polypeptide ◽  
Phylogenetic Affinities ◽  
Good Agreement

The amino acid sequence of plastocyanin from marrow was determined. It consists of a single polypeptide chain of mol.wt. 10284 containing 99 amino acid residues. The sequence was determined by using a Beckman 890C automatic sequencer and by dansyl–phenyl isothiocyanate analysis of peptides obtained by the enzymic digestion of purified CNBr fragments. The sequence is in good agreement with the amino acid composition, except that fewer residues of glutamic acid were found in the sequence than were suggested by the composition. Evidence for histidine-37 was weaker than for the rest of the sequence. A ‘tree’ of phylogenetic affinities was constructed by using several higher-plant plastocyanin sequences.

The Amino Acid Sequence of Cytochrome c-553 from the Chrysophycean Alga Monochrysis lutheri

1972 ◽  
Vol 50 (12) ◽  
pp. 1311-1325 ◽  
Author(s):  
M. V. Laycock
Keyword(s):  
Amino Acid ◽  
Cytochrome C ◽  
Amino Acid Sequence ◽  
Polypeptide Chain ◽  
Photosynthetic Apparatus ◽  
Amino Acid Residues ◽  
Unicellular Alga ◽  
Electron Carrier ◽  
Single Polypeptide Chain ◽  
Single Polypeptide

The amino acid sequence of cytochrome c-553, an electron carrier in the photosynthetic apparatus of the unicellular alga Monochrysis lutheri, has been determined. The protein consists of a single polypeptide chain of 83 amino acid residues. The sequence shows homology with mitochondrial cytochrome c at each end of the chain. The N-terminal glycine is not acetylated and corresponds to position 1 of mammalian cytochrome c when the cysteine residues of the two proteins are aligned.

scholarly journals Studies on the coagulant enzyme from Agkistrodon rhodostoma venom. Isolation and some properties of the enzyme

1973 ◽  
Vol 131 (4) ◽  
pp. 799-807 ◽  
Author(s):  
M. W. C. Hatton
Keyword(s):  
Amino Acid ◽  
Esterase Activity ◽  
Polypeptide Chain ◽  
Kinetic Properties ◽  
Amino Acid Residues ◽  
Commercial Preparation ◽  
Single Polypeptide Chain ◽  
Coagulant Activity ◽  
Terminal Amino ◽  
Single Polypeptide

1. Arvin, a commercial preparation of the coagulant activity from the venom of Agkistrodon rhodostoma, is shown to contain a non-coagulant caseinolytic fraction. 2. A method is described for the purification of the coagulant enzyme free from any detectable contaminating protein. 3. The coagulant enzyme is identified as a glycoprotein which probably consists of a single polypeptide chain containing approx. 29% by weight of carbohydrate. Amino acid and carbohydrate analyses are reported and the N- and C-terminal amino acid residues identified. 4. Electrophoresis on polyacrylamide gel reveals the polymorphic nature of the glycoprotein. Five forms of the enzyme are observed. 5. The coagulant action is correlated with an arginine esterase activity and kinetic properties are studied with both arginine and lysine esters as substrates. The inhibitory nature of guanidine and arginine toward the esterase activity is reported.

Identification, purification and properties of clone-specific glycoprotein antigens constituting the surface coat of Trypanosoma brucei

Parasitology ◽  
1975 ◽  
Vol 71 (3) ◽  
pp. 393-417 ◽  
Author(s):  
G. A. M. Cross
Keyword(s):  
Amino Acid ◽  
Trypanosoma Brucei ◽  
Polypeptide Chain ◽  
Polyacrylamide Gel Electrophoresis ◽  
Apparent Molecular Weight ◽  
Surface Glycoprotein ◽  
Surface Coat ◽  
Single Polypeptide Chain ◽  
Glycoprotein Antigen ◽  
Single Polypeptide

Soluble glycoproteins have been purified from a series of clones of Trypanosoma brucei 427. Each clone yielded a characteristic predominant glycoprotein which induced clone-specific immunity to trypanosome infection in mice. These glycoproteins were shown by specific labelling and enzyme digestion of cells to be the major components of the trypanosome surface coat. Each glycoprotein consisted of a single polypeptide chain having an apparent molecular weight of 65000 (as measured by SDS-polyacrylamide gel electrophoresis) and containing around 600 amino acid and 20 monosaccharide residues. Preliminary structural studies indicated large changes in amino acid sequence dispersed over a considerable length of the polypeptide chain. Proteolytic activity was demonstrated in semi-purified trypanosome extracts, providing one reason for the heterogeneity sometimes observed in surface glycoprotein antigen preparations.

scholarly journals The amino acid sequence of ferredoxin from Brassica napus (rape)

1980 ◽  
Vol 185 (1) ◽  
pp. 239-243 ◽  
Author(s):  
I Takruri ◽  
D Boulter
Keyword(s):  
Amino Acid ◽  
Brassica Napus ◽  
Amino Acid Sequence ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Plant Type ◽  
Single Polypeptide Chain ◽  
N Terminus ◽  
Single Polypeptide

The amino acid sequence of the ferredoxin of Brassica napus was determined by using a Beckman 890C sequencer in combination with the characterization of peptides obtained by tryptic and chymotryptic digestion of the protein; some peptides were subdigested with thermolysin. The molecule consists of a single polypeptide chain of 96 amino acid residues and has an unblocked N-terminus. The primary structure shows considerable similarity with other plant-type ferredoxins.

scholarly journals Comparative biochemistry of chondroitin sulphate–proteins of cartilage and notochord

1971 ◽  
Vol 125 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Martin B. Mathews
Keyword(s):  
Amino Acid ◽  
Chondroitin Sulphate ◽  
Hydroxyl Group ◽  
Amino Acid Residues ◽  
Short Sequence ◽  
Connective Tissues ◽  
Polysaccharide Chain ◽  
Single Polypeptide Chain ◽  
Single Polypeptide ◽  
Gradient Fractionation

Fragments that consisted mainly of two polysaccharide chains joined by a short polypeptide bridge (doublets) were prepared from chondroitin sulphate–proteins of lamprey, sturgeon, elasmobranch and ox connective tissues after hydrolysis with trypsin and chymotrypsin. Consideration of molecular parameters, compositions and behaviour on gel electrophoresis and density-gradient fractionation leads to a proposed parent structure for chondroitin sulphate–proteins. A single polypeptide chain of about 2000 amino acid residues contains alternating short and long repeating sequences. A short sequence consists of less than 10 amino acid residues with one N-terminal and one C-terminal serine residue, each of which carries a polysaccharide chain linked glycosidically to its hydroxyl group. This structure constitutes the doublet subunit. Some variation is introduced when the doublet subunit carries only a single polysaccharide chain. The long sequence contains about 35 amino acid residues and is subject to cleavage by trypsin and chymotrypsin. The main polypeptide is probably homologous in the vertebrate sub-phylum with strong conservation of structure suggested for the short sequence. However, polymorphism of polypeptide structures cannot be excluded.

scholarly journals Amino acid sequence of a four-iron-four-sulphur ferredoxin isolated from Bacillus stearothermophilus

1976 ◽  
Vol 159 (1) ◽  
pp. 55-63 ◽  
Author(s):  
T Hase ◽  
N Ohmiya ◽  
H Matsubara ◽  
R N Mullinger ◽  
K K Rao ◽  
...  
Keyword(s):  
Amino Acid ◽  
Bacillus Stearothermophilus ◽  
Cysteine Residue ◽  
Cysteine Residues ◽  
Amino Acid Residues ◽  
X Ray ◽  
Desulfovibrio Gigas ◽  
Single Polypeptide Chain ◽  
Single Polypeptide ◽  
First Time

1. The primary structure of a 4Fe-4S ferredoxin from Bacillus stearothermophilus was determined and shown to consist of a single polypeptide chain of 81 amino acid residues. The molecular weight of the holoprotein is about 9120. 2. There are only four cysteine residues in the molecule; three of these are located near the N-terminus as a Cys-X-X-Cys-X-X-Cys segment, and the fourth cysteine residue is followed by a proline and located in the C-terminal half. 3. The Fe-S chromophore in B. stearothermophilus ferredoxin was previously well characterized and was shown to consist of a single 4Fe-4S cluster. This ferredoxin sequence establishes for the first time the relative location of the four cysteine residues necessary to bind the 4Fe-4S cluster of a 4Fe ferredoxin, and is in agreement with the criteria for the relative positions of the cysteines proposed from X-ray-crystallographic studies on an 8Fe (two 4Fe-4S clusters) ferredoxin. 4. The sequence of B. stearothermophilus ferredoxin is homologous in many segments to that of other bacterial ferredoxins, the degree of homology being greater towards ferredoxins from Desulfovibrio gigas and photosynthetic bacteria than to Clostridial ferredoxins. 5. The presence of a relatively higher number of glutamic acid and lower number of cysteine residues in the molecule may explain the greater thermal stability and oxygen-insenstivity of this ferredoxin.

scholarly journals The amino acid sequence of plastocyanin from spinach. (Spinacia oleracea L.)

1975 ◽  
Vol 147 (2) ◽  
pp. 343-349 ◽  
Author(s):  
M D Scawen ◽  
J A Ramshaw ◽  
D Boulter
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Spinacia Oleracea ◽  
Sedimentation Equilibrium ◽  
Phenyl Isothiocyanate ◽  
Single Polypeptide Chain ◽  
Spinacia Oleracea L ◽  
Methionine Residues ◽  
Single Polypeptide

The amino acid sequence of spinach (Spinacia oleracea L.) plastocyanin was determined. It consists of a single polypeptide chain of 99 residues and has a sequence molecular weight of 10415. The sequence was determined by using a Beckman 890C automatic sequencer and by the dansyl--phenyl isothiocyanate analysis of peptides obtained by the enzymic digestion of purified CNBr fragments. Overlap through the two methionine residues was not shown. Sedimentation equilibrium in the ultracentrifuge gave a molecular weight for spinach plastocyanin of about 9000, in contrast with the value of 21000 reported previously by Katoh et al. (1962).

Hog pancreatic α-amylase. Preparation and characterization

1979 ◽  
Vol 44 (1) ◽  
pp. 288-293 ◽  
Author(s):  
Ivan Kluh
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Disulfide Bonds ◽  
Polypeptide Chain ◽  
Deae Cellulose ◽  
Amino Acid Residues ◽  
Single Polypeptide Chain ◽  
Single Polypeptide ◽  
End Group

Crystalline α-amylase (EC 3.2.1.1) was prepared from hog pancreas. The preparation obtained was resolved into two isozymes by chromatography on DEAE-cellulose. The molecular weight (51 500), amino acid composition, and terminal groups of both isozymes were determined. Both isozymes have a single polypeptide chain containing 460-465 amino acid residues. The amino acid composition of both isozymes is similar. None of them has a free N-terminal end group. Both isozymes are C-terminated with leucine. The molecule of each isozyme is cross-linked by 5 disulfide bonds and contains two sulfhydryl groups.

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