scholarly journals The regulatory proteins of the myofibril. Characterization and biological activity of the calcium-sensitizing factor (troponin A)

1972 ◽  
Vol 126 (1) ◽  
pp. 237-249 ◽  
Author(s):  
M. C. Schaub ◽  
S. V. Perry ◽  
W. Häcker
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Electrophoretic Mobility ◽  
Prolonged Exposure ◽  
Gel Filtration ◽  
Myofibrillar Protein ◽  
Inhibitory Factor ◽  
Regulatory Proteins ◽  
Protein System ◽  
Troponin Complex

1. Electrophoretically homogeneous calcium-sensitizing factor was prepared from the troponin complex by chromatography successively on sulphoethyl-Sephadex and on diethyl-(2-hydroxypropyl)aminoethyl-Sephadex in 6m-urea. It is a protein containing 53% of polar amino acids, of which a net excess consists of acidic residues. 2. On gel filtration the calcium-sensitizing factor was shown to be the only myofibrillar protein that bound 45Ca2+ tightly in the presence of 2–6m-urea. 3. Calcium-sensitizing factor effectively neutralized the effect of the inhibitory factor on the ATPase activities of actomyosin systems. Tropomyosin was essential for the regulation, by changes in the Ca2+ concentration, of the neutralizing effect of calcium-sensitizing factor on the inhibitory factor. 4. Prolonged exposure to chelators of Ca2+ produced an irreversibly modified form of calcium-sensitizing factor of higher electrophoretic mobility at pH8.6. The modified form neutralized the inhibitory factor action but this property could no longer be controlled by the Ca2+ concentration in the presence of tropomysin. 5. The calcium-sensitizing factor and tropomyosin could be replaced by their carboxymethylated derivatives in the relaxing-protein system.

scholarly journals The regulatory proteins of the myofibril. Characterization and properties of the inhibitory factor (troponin B)

1971 ◽  
Vol 123 (3) ◽  
pp. 367-377 ◽  
Author(s):  
M. C. Schaub ◽  
S. V. Perry
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Inhibitory Activity ◽  
Gel Filtration ◽  
Inhibitory Factor ◽  
Regulatory Proteins ◽  
Actomyosin Atpase ◽  
Troponin Complex

1. Gel-filtration results indicate that the major component of inhibitory-factor preparations isolated by dissociation of the troponin complex consisted of a protein of subunit weight 23000 daltons. By the same procedure a molecular weight of 18000 was obtained for the calcium-sensitizing factor. 2. The inhibitory factor is specific for the actomyosin type of ATPase and ITPase. It is effective on desensitized actomyosin, natural actomyosin and intact myofibrils. 3. For inhibition, the actomyosin ATPase must be stimulated by Mg2+, Ca2+ or Mn2+. The Co2+-, Cd2+- or Zn2+-stimulated ATPases are not affected. 4. Biological activity is stable to treatment with dissociating agents, heat, pH11, pH1 and carboxymethylation. 5. Increasing amounts of actin, but not myosin or tropomyosin, progressively neutralize the inhibitory activity when added to desensitized actomyosin or myofibrils.

On a Plasminogen Activator from Human Plasma

1979 ◽  
Vol 42 (05) ◽  
pp. 1607-1614 ◽  
Author(s):  
A Diaz Batista ◽  
G Hernandez Solana ◽  
J F Corral Almonte
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Human Plasma ◽  
Plasminogen Activator ◽  
Electrophoretic Mobility ◽  
Esterase Activity ◽  
Fibrinolytic Activity ◽  
Gel Filtration

SummaryA plasminogen activating substance was purified from the dialysates of the eluates of glass adsorbed kallikrein from fresh human plasma, by chromatography on QAE-Sephadex A-50 and gel filtration in Sephadex G-25. The preparation was concentrated by lyophilization. Its electrophoretic mobility was found to be similar to that of prealbumin. Its molecular weight appeared to be 15000–18000 daltons. The analysis of aminoacids of this activator showed that it contains a high proportion of acid amino acids. The purified activator showed esterase activity, fibrinolytic activity and kininogenase activity on heated human plasma. These activities were respectively equivalent to 150 μM BAEe/mg protein, 19 × 103 units of streptokinase/μg protein and 250 μg bradykinin/mg protein.

scholarly journals Human migration inhibitory factor: purification and immunochemical characterization.

1978 ◽  
Vol 147 (2) ◽  
pp. 541-553 ◽  
Author(s):  
L H Block ◽  
H Jaksche ◽  
S Bamberger ◽  
G Ruhenstroth-Bauer
Keyword(s):  
Electrophoretic Mobility ◽  
Migration Inhibitory Factor ◽  
Human Lymphocytes ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Peritoneal Macrophages ◽  
Human Migration ◽  
Inhibitory Factor ◽  
Migration Of Macrophages

Using gel filtration and preparative isotachophoresis, the migration inhibitory factor (MIF) was highly purified from human lymphocytes activated with concanavalin A. MIF is an acidic protein with a mol wt of approximately equal to 25,000 daltons as determined by gel filtration and analytical polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The protein inhibits migration of macrophages in the capillary test and in addition, has a slowing effect on the electrophoretic mobility of guinea pig peritoneal macrophages. Rabbit antibodies specific for this protein, as determined by immunochemical techniques, neutralized the biological effect of MIF on migration and on the electrophoretic mobility of macrophages.

scholarly journals The regulatory proteins of the myofibril. Separation and biological activity of the components of inhibitory-factor preparations

1972 ◽  
Vol 127 (1) ◽  
pp. 215-228 ◽  
Author(s):  
J. M. Wilkinson ◽  
S. V. Perry ◽  
H. A. Cole ◽  
I. P. Trayer
Keyword(s):  
Molecular Weight ◽  
Active Component ◽  
Inhibitory Factor ◽  
Regulatory Proteins ◽  
Additional Component ◽  
Limited Evidence ◽  
Molecular Weights ◽  
Molar Basis ◽  
Troponin Complex ◽  
Cysteine Content

1. Inhibitory-factor preparations isolated from myofibrils were shown to consist principally of proteins with molecular weights of 37000 and 23000. Under certain preparative procedures an additional component of molecular weight 14000 was present. 2. The 23000-dalton protein, the inhibitory factor, was the major active component. Its activity was enhanced by tropomyosin. 3. The 14000-dalton component also possessed inhibitory activity, although less than that of the 23000-dalton component when compared on a molar basis. Its activity was not always enhanced by tropomyosin. The 14000-dalton component could not be detected in whole fresh myofibrils and the limited evidence available is compatible with its formation during the preparation of the troponin complex. 4. The 37000-dalton component could not replace the inhibitory factor, calcium-sensitizing factor or tropomyosin as components of the relaxing-protein system. 5. All three components had distinctive amino acid compositions, particularly in their cysteine content.

scholarly journals The relaxing protein system of striated muscle. Resolution of the troponin complex into inhibitory and calcium ion-sensitizing factors and their relationship to tropomyosin

1969 ◽  
Vol 115 (5) ◽  
pp. 993-1004 ◽  
Author(s):  
M. C. Schaub ◽  
S V Perry
Keyword(s):  
Ionic Strength ◽  
Adenosine Triphosphatase ◽  
Striated Muscle ◽  
Inhibitory Effect ◽  
Inhibitory Factor ◽  
Adenosine Triphosphatase Activity ◽  
Protein System ◽  
Maximum Inhibition ◽  
Troponin Complex ◽  
Low Ionic Strength

1. A method involving isoelectric precipitation and chromatography on SE-Sephadex (sulphoethyl-Sephadex) is described for the preparation of the troponin complex free of tropomyosin from low-ionic-strength extracts of natural actomyosin and myofibrils. 2. Purified troponin complex required tropomyosin to inhibit the Mg2+-stimulated adenosine triphosphatase activity and superprecipitation of desensitized actomyosin in the presence of ethanedioxybis(ethylamine)tetra-acetate. An upper limit of 35000 for the ‘molecular weight’ of the troponin complex was derived from the amounts required to bring about 50% of the maximum inhibition of the Mg2+-stimulated adenosine triphosphatase activity of desensitized actomyosin of known concentration. 3. In the presence of dissociating reagents the troponin complex could be dissociated into inhibitory and Ca2+-sensitizing factors, which could be isolated separately on SE-Sephadex. The inhibitory factor inhibited the Mg2+-stimulated adenosine triphosphatase activity and superprecipitation of desensitized actomyosin independently of the concentration of free Ca2+ in the medium. 4. The Ca2+-sensitizing factor changed its electrophoretic mobility on polyacrylamide gel in the presence of ethanedioxybis(ethylamine)tetra-acetate. It formed a complex with the inhibitory factor at low ionic strength and the original biological activity of the troponin complex could be restored on mixing the inhibitory factor with the Ca2+-sensitizing factor in the ratio of about 3:2. 5. Evidence is presented indicating that the ability of tropomyosin preparations to restore relaxing-protein-system activity to the troponin complex and their inhibitory effect on the Ca2+-stimulated adenosine triphosphatase activity of desensitized actomyosin are two properties of different stability to preparative procedures and tryptic digestion. This suggests that the relaxing protein system of muscle may contain another as yet uncharacterized component.

Synthesis and biological activity of new metallocenic angiotensin II analogs

1988 ◽  
Vol 53 (11) ◽  
pp. 2914-2919 ◽  
Author(s):  
Pierrette Maes ◽  
Annie Ricouart ◽  
Emmanuel Escher ◽  
André Tartar ◽  
Christian Sergheraert
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Angiotensin Ii ◽  
Solid Phase ◽  
Rabbit Aorta ◽  
Phase Method ◽  
Solid Phase Method

Analogs of angiotensin II in which phenylalanine in position 8 was replaced with cymantrenylalanine or with its triphenylphosphine photosubstitution product were synthesized by the solid-phase method. On rabbit aorta strips, these peptides were found to be pure antagonists of angiotensin II. Their relative affinities are higher than most other analogs substituted in position 8 with bulky amino-acids.

Tissue Deposition of Zinc from a Zinc Chelate and from Inorganic Zinc in Rats

1994 ◽  
Vol 1994 ◽  
pp. 171-171 ◽  
Author(s):  
Ronan Power ◽  
Kevin Cashman ◽  
Albert Flynn
Keyword(s):  
Amino Acids ◽  
Tissue Distribution ◽  
Wistar Rats ◽  
Gel Filtration ◽  
Normal Diet ◽  
Farm Animals ◽  
Trace Minerals ◽  
Inorganic Salts ◽  
Male Wistar Rats ◽  
Differential Tissue

Some reports have suggested differential tissue deposition of dietary trace minerals such as Zinc (Zn) when supplied to farm animals either chelated to amino acids or as inorganic salts. To test this hypothesis, an experiment was conducted to determine the ultimate tissue distribution of Zinc in rats fed either a radioactively-labeled 65Zn-chelate or 65ZnSO4. The 65Zn-chelate was prepared by heating a solution of 65ZnSO4 and an equimolar mixture of glycine and methionine for 5 minutes at 90°C. The resulting chelate was then separated from unincorporated 65ZnSO4 by gel filtration chromatography. Ten 25-d old male wistar rats (mean weight 34.5 g) were randomized by weight into two groups (n = 5/group), fasted for 18 hours and given 0.4 ml (8 μg Zn, 1 μCi65Zn) of one or other labelled solution by gavage. Four hours later, animals were returned to their normal diet for the duration of the experiment. The 65Zn activity of the animals was determined two hours after administration and daily thereafter for 7 days.

scholarly journals Transforming growth factor alpha: mutation of aspartic acid 47 and leucine 48 results in different biological activities.

1988 ◽  
Vol 8 (3) ◽  
pp. 1247-1252 ◽  
Author(s):  
E Lazar ◽  
S Watanabe ◽  
S Dalton ◽  
M B Sporn
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Amino Acid ◽  
Growth Factor ◽  
Aspartic Acid ◽  
Transforming Growth Factor ◽  
Biologically Active ◽  
Single Amino Acid ◽  
Transforming Growth Factor Alpha ◽  
Factor Alpha

To study the relationship between the primary structure of transforming growth factor alpha (TGF-alpha) and some of its functional properties (competition with epidermal growth factor (EGF) for binding to the EGF receptor and induction of anchorage-independent growth), we introduced single amino acid mutations into the sequence for the fully processed, 50-amino-acid human TGF-alpha. The wild-type and mutant proteins were expressed in a vector by using a yeast alpha mating pheromone promoter. Mutations of two amino acids that are conserved in the family of the EGF-like peptides and are located in the carboxy-terminal part of TGF-alpha resulted in different biological effects. When aspartic acid 47 was mutated to alanine or asparagine, biological activity was retained; in contrast, substitutions of this residue with serine or glutamic acid generated mutants with reduced binding and colony-forming capacities. When leucine 48 was mutated to alanine, a complete loss of binding and colony-forming abilities resulted; mutation of leucine 48 to isoleucine or methionine resulted in very low activities. Our data suggest that these two adjacent conserved amino acids in positions 47 and 48 play different roles in defining the structure and/or biological activity of TGF-alpha and that the carboxy terminus of TGF-alpha is involved in interactions with cellular TGF-alpha receptors. The side chain of leucine 48 appears to be crucial either indirectly in determining the biologically active conformation of TGF-alpha or directly in the molecular recognition of TGF-alpha by its receptor.

scholarly journals Translational and Structural Requirements of the Early Nodulin Gene enod40, a Short-Open Reading Frame-Containing RNA, for Elicitation of a Cell-Specific Growth Response in the Alfalfa Root Cortex

2001 ◽  
Vol 21 (1) ◽  
pp. 354-366 ◽  
Author(s):  
Carolina Sousa ◽  
Christina Johansson ◽  
Celine Charon ◽  
Hamid Manyani ◽  
Christof Sautter ◽  
...  
Keyword(s):  
Amino Acids ◽  
Biological Activity ◽  
Rna Structure ◽  
Open Reading Frames ◽  
In Vitro Translation ◽  
Cortical Cells ◽  
Root Cortex ◽  
Reading Frame ◽  
Early Nodulin

ABSTRACT A diversity of mRNAs containing only short open reading frames (sORF-RNAs; encoding less than 30 amino acids) have been shown to be induced in growth and differentiation processes. The early nodulin geneenod40, coding for a 0.7-kb sORF-RNA, is expressed in the nodule primordium developing in the root cortex of leguminous plants after infection by symbiotic bacteria. Ballistic microtargeting of this gene into Medicago roots induced division of cortical cells. Translation of two sORFs (I and II, 13 and 27 amino acids, respectively) present in the conserved 5′ and 3′ regions ofenod40 was required for this biological activity. These sORFs may be translated in roots via a reinitiation mechanism. In vitro translation products starting from the ATG of sORF I were detectable by mutating enod40 to yield peptides larger than 38 amino acids. Deletion of a Medicago truncatula enod40 region between the sORFs, spanning a predicted RNA structure, did not affect their translation but resulted in significantly decreased biological activity. Our data reveal a complex regulation of enod40action, pointing to a role of sORF-encoded peptides and structured RNA signals in developmental processes involving sORF-RNAs.

Characterization of an isozyme of S-adenosylmethionine synthetase from rat liver

1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Enzymatic Synthesis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Aromatic Amino Acids ◽  
Adenosylmethionine Synthetase ◽  
Cellulose Column

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.

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