scholarly journals Specific inhibition of L-type pyruvate kinase by the triazine dye Procion Blue MX-R.

1984 ◽  
Vol 223 (2) ◽  
pp. 359-367 ◽  
Author(s):  
M F Byford ◽  
D P Bloxham
Keyword(s):  
Pyruvate Kinase ◽  
Large Scale ◽  
Tryptic Peptide ◽  
Peptide Mapping ◽  
Specific Interaction ◽  
Histidine Residue ◽  
Specific Inhibition ◽  
Enzyme Modification ◽  
Type Form ◽  
Triazine Dye

Incubation of the triazine dye Procion Blue MX-R with L- and M-type pyruvate kinase resulted in rapid time- and dye-concentration-dependent loss of activity. L-type pyruvate kinase was protected only by a low concentration of Mg2+; this was not the case with the M-type enzyme. Modification of the L-type form resulted in the incorporation of 1.54 +/- 0.057 mol of dye/mol of enzyme subunit in the absence of Mg2+, but only 0.73 +/- 0.024 mol of dye/mol of enzyme subunit in the presence of Mg2+. Tryptic peptide mapping of L-type pyruvate kinase modified in the presence and in the absence of Mg2+ further indicated that there were two sites modified in the enzyme, one of which was protected by Mg2+. The pKa of the nucleophile involved in the modification was calculated to be 7.1, implicating the possible involvement of a histidine residue. L-type enzyme was bound to Sepharose-immobilized Procion Blue MX-R specifically in the presence of Mg2+, whereas binding of the M-type enzyme was Mg2+-independent. The specific interaction of L-type pyruvate kinase with the dye was exploited in the large-scale purification of the enzyme and in the isolation of the phosphorylated enzyme.

scholarly journals A comparative study of aldolase from human muscle and liver

1973 ◽  
Vol 133 (3) ◽  
pp. 429-439 ◽  
Author(s):  
Peter A. M. Eagles ◽  
Muzaffar Iqbal
Keyword(s):  
Human Liver ◽  
Large Scale ◽  
Human Skeletal Muscle ◽  
Tryptic Peptide ◽  
Peptide Mapping ◽  
Structural Similarity ◽  
Human Muscle ◽  
Rabbit Muscle ◽  
X Ray ◽  
Crystalline Forms

Aldolase was purified from human skeletal muscle and human liver by techniques capable of processing large quantities (10–20kg) of tissue. The methods used also proved convenient for isolating aldolase on a large scale from other mammalian and avian sources. Aldolase from both human liver and muscle was crystallized; each gave two crystalline forms, depending on the conditions of crystallization. X-ray studies on the muscle aldolase crystals suggest a close structural similarity between human and rabbit muscle aldolase. Aldolases from human muscle and liver have similar pH optima and pH stability but their stability to heat treatment differs. The effect of heat on the enzymes may therefore provide an easy means of distinguishing them. The kinetic constants Km and kcat. for these aldolases are similar to other mammalian aldolases. Amino acid analyses and tryptic peptide ‘mapping’ show that the primary structures of the two aldolases differ greatly.

Temperature-dependent instability of the cTnI subunit in NIST SRM2921 characterized by tryptic peptide mapping

2012 ◽  
Vol 902 ◽  
pp. 147-150 ◽  
Author(s):  
Yuri E.M. van der Burgt ◽  
Christa M. Cobbaert ◽  
Hans Dalebout ◽  
Nico Smit ◽  
André M. Deelder
Keyword(s):  
Tryptic Peptide ◽  
Peptide Mapping ◽  
Temperature Dependent

Development of Defect Interaction Criteria for Pipeline Girth Welds Subjected to Plastic Collapse Conditions

2006 ◽  
Author(s):  
Wim De Waele ◽  
Rudi Denys ◽  
Antoon Lefevre
Keyword(s):  
Large Scale ◽  
Specific Interaction ◽  
Ductile Failure ◽  
Elastic Interaction ◽  
Tensile Tests ◽  
Ductile Material ◽  
Plastic Collapse ◽  
Material Behaviour ◽  
Defect Interaction ◽  
Girth Welds

Multiple defects in welds, when detected, have to be assessed for interaction. Current defect interaction rules are largely based on linear elastic fracture mechanics principles (brittle material behaviour). Pipeline welding codes, however, specify toughness requirements to ensure ductile failure by plastic collapse. Therefore, the use of current (elastic) interaction rules for ductile girth welds can lead to unnecessary and possibly harmful weld repairs or cutouts. This paper reports on an assessment of the engineering significance of existing pipeline specific interaction criteria and on the development of new criteria. Rules for the interaction of coplanar surface breaking defects and ductile material behaviour have been developed on the basis of the performance requirement of remote yielding. The results of large-scale tensile tests illustrate that current interaction rules have a high degree of conservatism for plastic collapse conditions. The test data have been used to demonstrate that the developed procedure can be safely used for ductile girth welds.

Analysis of C3b/C4b receptor (CR1) polymorphic variants by tryptic peptide mapping

1986 ◽  
Vol 23 (6) ◽  
pp. 661-668 ◽  
Author(s):  
M.W. Nickells ◽  
T. Seya ◽  
V.M. Holers ◽  
J.P. Atkinson
Keyword(s):  
Tryptic Peptide ◽  
Peptide Mapping ◽  
Polymorphic Variants

Large-scale purification, oligomerization equilibria, and specific interaction of the LexA repressor of Escherichia coli

Biochemistry ◽  
1985 ◽  
Vol 24 (11) ◽  
pp. 2812-2818 ◽  
Author(s):  
M. Schnarr ◽  
J. Pouyet ◽  
M. Granger-Schnarr ◽  
M. Daune
Keyword(s):  
Escherichia Coli ◽  
Large Scale ◽  
Specific Interaction ◽  
Lexa Repressor

scholarly journals Identification of cysteine as the reactive group in pyruvate kinase alkylated by 5-chloro-4-oxopentanoic acid

1976 ◽  
Vol 159 (2) ◽  
pp. 213-219 ◽  
Author(s):  
R A Chalkley ◽  
D P Bloxham
Keyword(s):  
Pyruvate Kinase ◽  
Peptide Mapping ◽  
Periodate Oxidation ◽  
Performic Acid ◽  
Acid Oxidation ◽  
Rabbit Muscle ◽  
Pentanoic Acid ◽  
Reactive Group ◽  
Muscle Pyruvate Kinase ◽  
Nabh4 Reduction

4-Hydroxypentanoic acid alanine thioether was synthesized and characterized by n.m.r. spectroscopy. This derivative corresponded to the modified amino acid obtained by allowing 5-chloro-4-oxo[3,5-3H]pentanoic acid to react with rabbit muscle pyruvate kinase. Performic acid oxidation of 4-oxo[3,5-3H]pentanoic acid alanine thioether in pyruvate kinase gave [3H]succinate (67%) and [3H]carboxymethylcysteine (33%) as expected. Evidence is presented to show that NaBH4 reduction followed by periodate oxidation and analysis of radioactive formaldehyde production may provide a convenient method for distinguishing between thiol and amino alkylation by halogenomethyl ketone compounds. Peptide ‘mapping’ confirms that the modification by 5-chloro-4-oxopentanoic acid occurs primarily at one region of pyruvate kinase.

Beyond "Kamikaze Migrants": Risk Taking in West African Boat Migration to Europe

2012 ◽  
Vol 71 (4) ◽  
pp. 407-416 ◽  
Author(s):  
María Hernández-Carretero ◽  
Jørgen Carling
Keyword(s):  
Canary Islands ◽  
Risk Taking ◽  
Large Scale ◽  
Specific Interaction ◽  
West African ◽  
Social Phenomenon ◽  
African Countries ◽  
Context Specific

In recent years, tens of thousands of young Africans have left the shores of Senegal and other West African countries in small boats headed for Spain's Canary Islands. Most have spent a week or more at sea, and unknown numbers have died in the attempt. Given the danger of the journey, we ask how it could become a large-scale social phenomenon. The analysis focuses on how prospective migrants assess and relate to the risks of migration. We show that risk taking is shaped by context-specific interaction of disparate factors. These include economic obstacles to reaching social adulthood, notions of masculinity, pride and honor, and religion, in the form of sufi Islam.

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