Tryptic peptide mapping of core polypeptide from heterogeneous ribonucleoprotein particles

1981 ◽  
Vol 1 (5) ◽  
pp. 407-411 ◽  
Author(s):  
Andrew F. Wilks ◽  
John T. Knowler
Keyword(s):  
Tryptic Peptide ◽  
Peptide Mapping ◽  
Ribonucleoprotein Particles

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

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

scholarly journals Phosphorylation of rat liver heterogeneous nuclear ribonucleoproteins A2 and C can be modulated by calmodulin.

1995 ◽  
Vol 15 (2) ◽  
pp. 661-670 ◽  
Author(s):  
R Bosser ◽  
M Faura ◽  
J Serratosa ◽  
J Renau-Piqueras ◽  
M Pruschy ◽  
...  
Keyword(s):  
Rat Liver ◽  
Peptide Mapping ◽  
Specific Protein ◽  
Casein Kinase ◽  
Casein Kinase 2 ◽  
Dependent Manner ◽  
Cell Nuclei ◽  
Ribonucleoprotein Particles ◽  
C Proteins

It was previously reported that the phosphorylation of three proteins of 36, 40 to 42, and 50 kDa by casein kinase 2 is inhibited by calmodulin in nuclear extracts from rat liver cells (R. Bosser, R. Aligué, D. Guerini, N. Agell, E. Carafoli, and O. Bachs, J. Biol. Chem. 268:15477-15483, 1993). By immunoblotting, peptide mapping, and endogenous phosphorylation experiments, the 36- and 40- to 42-kDa proteins have been identified as the A2 and C proteins, respectively, of the heterogeneous nuclear ribonucleoprotein particles. To better understand the mechanism by which calmodulin inhibits the phosphorylation of these proteins, they were purified by using single-stranded DNA chromatography, and the effect of calmodulin on their phosphorylation by casein kinase 2 was analyzed. Results revealed that whereas calmodulin inhibited the phosphorylation of purified A2 and C proteins in a Ca(2+)-dependent manner, it did not affect the casein kinase 2 phosphorylation of a different protein substrate, i.e., beta-casein. These results indicate that the effect of calmodulin was not on casein kinase 2 activity but on specific protein substrates. The finding that the A2 and C proteins can bind to a calmodulin-Sepharose column in a Ca(2+)-dependent manner suggests that this association could prevent the phosphorylation of the proteins by casein kinase 2. Immunoelectron microscopy studies have revealed that such interactions could also occur in vivo, since calmodulin and A2 and C proteins colocalize on the ribonucleoprotein particles in rat liver cell nuclei.

Phosphofructokinase from Escherichia coli: Further evidence for identical subunits

1978 ◽  
Vol 56 (8) ◽  
pp. 836-838 ◽  
Author(s):  
Bruce N. Thornburgh ◽  
Licia Liu Wu ◽  
Charles C. Griffin
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Affinity Chromatography ◽  
Tryptic Peptide ◽  
Peptide Mapping

A procedure for the purification of Escherichia coli phosphofructokinase by affinity chromatography is described. The results of amino acid analyses of the purified protein and tryptic peptide mapping suggest that the tetrameric phosphofructokinase is composed of chemically identical subunits. In addition, the reaction product, ADP, was observed to bind to 4.1 ± 0.1 equal and independent sites on the enzyme.

Structure And Function Of The Human Platelet Von Willebrand Factor Receptor

1981 ◽  
Author(s):  
K J Clemetson ◽  
H Y Naim ◽  
E F Lüscher
Keyword(s):  
Von Willebrand Factor ◽  
Tryptic Peptide ◽  
Peptide Mapping ◽  
Human Platelet ◽  
Glycoprotein Ib ◽  
Proteolytic Fragment ◽  
Similar Treatment ◽  
Α Chain ◽  
Von Willebrand ◽  
Willebrand Factor

The interactions between platelets and subendothelium involving von Willebrand factor play an important role in haemostasis and thrombosis. The identity of the von Willebrand factor receptor with human platelet membrane glycoprotein Ib has now been fairly conclusively established but the precise nature of the binding site and the changes induced by binding have yet to be demonstrated.Asialoglycoprotein Ib and asialoglycocalicin have been isolated from neuraminidase treated platelets by affinity-chromatography on peanut agglutinin and compared by tryptic peptide mapping. The results clearly show that glycocalicin is closely related to the α-chain of glycoprotein Ib and is probably a proteolytic fragment of it. Unreduced and reduced glycocalicin showed minor differences in their tryptic peptide maps indicating that glycocalicin and by extension the α-chain of glycoprotein Ib probably contain at least one intramolecular disulphide bond.Treatment of platelets with reducing agents such as dithiothreitol results in loss of response to bovine von Willebrand factor. Similar treatment of surface-labelled platelets did not release any glycoprotein subunits into the supernatant, implying that disulphide bridge-linked subunits are tightly associated with the membrane or with other subunits. Hydrophobic chromatography of reduced, purified glycoprotein Ib indicates that both α and β subunits are hydrophobic and thus probably integral membrane glycoproteins. Intact disulphide bridges seem to be a prerequisite for von Willebrand factor receptor activity.

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