Molecular conformation of bovine A1 basic protein, a coiling macromolecule in aqueous solution

Biochemistry ◽  
1975 ◽  
Vol 14 (11) ◽  
pp. 2542-2546 ◽  
Author(s):  
W. R. Krigbaum ◽  
Thomas S. Hsu
Keyword(s):  
Aqueous Solution ◽  
Molecular Conformation ◽  
Basic Protein ◽  
Protein A

scholarly journals Quantification of Proteolytically Active Pregnancy-Associated Plasma Protein-A with an Assay Based on Quenched Fluorescence

2007 ◽  
Vol 53 (5) ◽  
pp. 947-954 ◽  
Author(s):  
Claus Gyrup ◽  
Michael Christiansen ◽  
Claus Oxvig
Keyword(s):  
Proteolytic Activity ◽  
Plasma Protein ◽  
Basic Protein ◽  
Biological Function ◽  
Limit Of Detection ◽  
Protein A ◽  
Maternal Serum ◽  
Serum Samples ◽  
A Subunit ◽  
Eosinophil Major Basic Protein

Abstract Background: Maternal serum concentrations of pregnancy-associated plasma protein-A (PAPP-A, pappalysin-1, EC 3.4.24.79) are used to predict the occurrence of Down syndrome. In pregnancy, PAPP-A primarily circulates as a covalent 2:2 complex with the proform of eosinophil major basic protein (proMBP), which inhibits the proteolytic activity of PAPP-A. At term, however, ∼1% of PAPP-A exists as an active, uncomplexed dimer with proteolytic activity directed specifically toward insulin-like growth factor binding protein (IGFBP)-4 and IGFBP-5. No assays have been developed that allow quantification of PAPP-A proteolytic activity. Methods: We developed a sensitive and specific immunocapture assay for PAPP-A activity based on intramolecular quenched fluorescence. We used a 26-residue synthetic peptide derived from IGFBP-4 in which specific positions on each side of the PAPP-A cleavage site were substituted with 3-nitrotyrosine and o-aminobenzoic acid. Results: The assay detected the activity of recombinant PAPP-A as well as PAPP-A in serum samples from pregnant women. The limit of detection (mean signal of blank plus 3 SD) of the active PAPP-A subunit was 13 pmol/L, and the intra- and interassay CVs were <10% and <15%, respectively. Interestingly, the fraction of active PAPP-A decreased gradually from week 7 to week 19 of pregnancy. Conclusions: This method allows the measurement of PAPP-A enzymatic activity and because of its specificity it is relevant to the study of the biological function of PAPP-A. The method may also be useful in the diagnosis of pregnancy disorders.

The proform of eosinophil major basic protein: a new maternal serum marker for Down syndrome

1999 ◽  
Vol 19 (10) ◽  
pp. 905-910 ◽  
Author(s):  
Michael Christiansen ◽  
Claus Oxvig ◽  
Jill M. Wagner ◽  
Qiu-Ping Qin ◽  
Tri H. Nguyen ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Basic Protein ◽  
Protein A ◽  
Serum Marker ◽  
Maternal Serum ◽  
Major Basic Protein ◽  
Eosinophil Major Basic Protein

scholarly journals Proteolytic and peroxidatic reactions of commercial horseradish peroxidase with myelin basic protein

1978 ◽  
Vol 169 (3) ◽  
pp. 567-575 ◽  
Author(s):  
Wendy Cammer ◽  
Lesley Z. Bieler ◽  
William T. Norton
Keyword(s):  
Horseradish Peroxidase ◽  
Myelin Basic Protein ◽  
Basic Protein ◽  
Protein A ◽  
Low Molecular Weight ◽  
Basic Proteins ◽  
Molecular Weights ◽  
Low Concentrations ◽  
High Concentrations ◽  
A Minor

Degradation of myelin basic protein during incubations with high concentrations of horseradish peroxidase has been demonstrated [Johnson & Cammer (1977) J. Histochem. Cytochem.25, 329–336]. Possible mechanisms for the interaction of the basic protein with peroxidase were investigated in the present study. Because the peroxidase samples previously observed to degrade basic protein were mixtures of isoenzymes, commercial preparations of the separated isoenzymes were tested, and all three degraded basic protein, but to various extents. Three other basic proteins, P2 protein from peripheral nerve myelin, lysozyme and cytochrome c, were not degraded by horseradish peroxidase under the same conditions. Inhibitor studies suggested a minor peroxidatic component in the reaction. Therefore the peroxidatic reaction with basic protein was studied by using low concentrations of peroxidase along with H2O2. Horseradish peroxidase plus H2O2 caused the destruction of basic protein, a reaction inhibited by cyanide, azide, ferrocyanide, tyrosine, di-iodotyrosine and catalase. Lactoperoxidase plus H2O2 and myoglobin plus H2O2 were also effective in destroying the myelin basic protein. Low concentrations of horseradish peroxidase plus H2O2 were not active against other basic proteins, but did destroy casein and fibrinogen. Although high concentrations of peroxidase alone degraded basic protein to low-molecular-weight products, suggesting the operation of a proteolytic enzyme contaminant in the absence of H2O2, incubations with catalytic concentrations of peroxidase in the presence of H2O2 converted basic protein into products with high molecular weights. Our data suggest a mechanism for the latter, peroxidatic, reaction where polymers would form by linking the tyrosine side chains in basic-protein molecules. These data show that the myelin basic protein is unusually susceptible to peroxidatic reactions.

Molecular Conformation of 4-Thiouridine in Aqueous Solution

1971 ◽  
Vol 49 (14) ◽  
pp. 2449-2452 ◽  
Author(s):  
F. E. Hruska ◽  
K. K. Ogilvie ◽  
A. A. Smith ◽  
H. Wayborn
Keyword(s):  
Aqueous Solution ◽  
Long Range ◽  
Crystalline State ◽  
Molecular Conformation ◽  
Spin Coupling ◽  
Pyrimidine Nucleoside ◽  
Coupling Interaction ◽  
X Ray ◽  
Anti Conformation ◽  
Spin Spin Coupling

β-4-Thiouridine is a component of several tRNA molecules. A recent X-ray study has shown that this pyrimidine nucleoside favors the syn conformation in the crystalline state. The 100 and 220 MHz p.m.r. data and a comparison with those of uridine are presented here. A long-range five-bond spin–spin coupling interaction between the H-5 and -1′ hydrogens is noted. The results are consistent with an anti conformation for 4-thiouridine in an aqueous solution.

Ribo-2′-deoxyribo hybrid dinucleoside monophosphates. Proton magnetic resonance studies of 3′,5′- and 2′,5′-uridylyl-2′-deoxythymidine

1978 ◽  
Vol 56 (4) ◽  
pp. 522-529 ◽  
Author(s):  
James Peeling ◽  
Frank E. Hruska ◽  
Peter C. Loewen
Keyword(s):  
Aqueous Solution ◽  
Magnetic Resonance ◽  
Proton Magnetic Resonance ◽  
Molecular Conformation ◽  
The Other ◽  
Magnetic Resonance Studies ◽  
Dinucleoside Monophosphates ◽  
Standard Techniques

This 1Hmr study initiates our examination of the conformations of dinucleoside monophosphates possessing ribo 2′- or 3′-nucleotidyl units linked to 5′-nucleotidyl units possessing the 2′-deoxyribo sugar. The syntheses of uridylyl-3′,5′-2′-deoxythymidine (3′,5′-UpdT) and its 2′,5′-isomer, 2′,5′-UpdT, were carried out with standard techniques. The 1Hmr data were obtained at frequencies up to 270 MHz and used to derive the dominant conformation of the dimers in aqueous solution. Comparison with data for the component mononucleotides reveals that dimerization does not lead to drastic changes in the molecular conformation. Literature data for dimers possessing only the ribo sugar (3′,5′-UpU) and the 2′-deoxyribo sugar (3′,5′-d(TpT)) are also presented. The results indicate that, at least for our dipyrimidine dimers, the molecular conformation of a particular fragment is not critically dependent on the nature (ribo or 2′-deoxyribo) of the other nucleotide unit.

Molecular Conformation-Controlled Vesicle/Micelle Transition of Cationic Trimeric Surfactants in Aqueous Solution

Langmuir ◽  
2010 ◽  
Vol 26 (11) ◽  
pp. 7922-7927 ◽  
Author(s):  
Chunxian Wu ◽  
Yanbo Hou ◽  
Manli Deng ◽  
Xu Huang ◽  
Defeng Yu ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Molecular Conformation ◽  
Trimeric Surfactants

N.M.R. studies of myelin basic protein. XII. Spectra in aqueous solution of a synthetic octapeptide encephalitogenic in the Lewis rat

1984 ◽  
Vol 37 (7) ◽  
pp. 1427 ◽  
Author(s):  
J Bremer ◽  
WJ Moore
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Bonds ◽  
Synthetic Peptide ◽  
Basic Protein ◽  
Peptide Bond ◽  
Lewis Rat ◽  
Compact Structure ◽  
Linear Peptide ◽  
Temperature Dependences ◽  
Intramolecular Hydrogen

A synthetic peptide Ala-Gln-Arg-Pro-Gln-Asp-Glu-Asn encephalitogenic in the Lewis rat has been studied in aqueous solutions by 1H and 13C n.m.r. The configuration about the Arg-Pro peptide bond is > 99% trans. The temperature dependences and titration shifts of NH resonances areconsistent with occurrence of a number of intramolecular hydrogen bonds, leading to an unusually compact structure for a linear peptide in aqueous solution.

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