scholarly journals Active Leptin Fragments Resistant to Proteolytic Enzymes Present in Human Plasma

2015 ◽  
Author(s):  
Paula Y. Tokuyama ◽  
Edgar J. Paredes-Gamero ◽  
Antonio Miranda
Keyword(s):  
Human Plasma ◽  
Proteolytic Enzymes

scholarly journals Immunochemical studies of antisera to human fibrinopeptide-B

Blood ◽  
1982 ◽  
Vol 59 (5) ◽  
pp. 1006-1012
Author(s):  
VP Jr Butler ◽  
DA Weber ◽  
HL Nossel ◽  
D Tse-Eng ◽  
KS LaGamma ◽  
...  
Keyword(s):  
Human Plasma ◽  
Proteolytic Enzymes ◽  
Terminal Segment ◽  
Plasma Samples ◽  
Beta Chain ◽  
Human Fibrinogen ◽  
Carboxypeptidase B ◽  
Immunochemical Detection ◽  
Proteins And Peptides

The immunochemical specificity of rabbit antisera to human fibrinopeptide-B (FPB) has been studied by comparing the relative abilities of FPB and of various proteins and peptides containing the NH2-terminal segment of the B beta-chain of human fibrinogen to inhibit the binding of a radioiodinated FPB derivative by each of seven anti- FPB sera. Anti-FBP sera varied in the extent to which they cross- reacted with fibrinogen, the NH2-terminal disulfide knot of fibrinogen (N-DSK), B beta 1(Pyr)-118(Met), B beta 1(Pyr)-42(Arg), and desarginyl- FPB. Anti-FPB sera have been identified that discriminate effectively between FPB and larger FBP-containing peptides; such antisera can be used to measure FPB in the absence of the larger peptides or to demonstrate the presence of larger peptides such as B beta 1(Pyr)- 42(Arg) in extracts of clinical plasma samples by means of an increase in FPB immunoreactivity following thrombin treatment. One anti-FPB serum has been identified that is capable of detecting desarginyl-FPB, and this antiserum has been used in the development of a radioimmunoassay for desarginyl-FPB. Thus, by precisely defining the specificity of anti-FPB sera, it has been possible to identify antisera that are useful, not only in the measurement of FPB, but also in the detection of other important related molecules, such as B beta 1(Pyr)- 42(Arg) and desarginyl-FPB. The immunochemical detection of these FPB- related peptides should provide useful information concerning the action of proteolytic enzymes, such as plasmin on the NH2-terminal segment of the B beta-chain of fibrinogen, and of carboxypeptidase-B on free FPB, in human plasma.

scholarly journals Immunochemical studies of antisera to human fibrinopeptide-B

Blood ◽  
1982 ◽  
Vol 59 (5) ◽  
pp. 1006-1012 ◽  
Author(s):  
VP Jr Butler ◽  
DA Weber ◽  
HL Nossel ◽  
D Tse-Eng ◽  
KS LaGamma ◽  
...  
Keyword(s):  
Human Plasma ◽  
Proteolytic Enzymes ◽  
Terminal Segment ◽  
Plasma Samples ◽  
Beta Chain ◽  
Human Fibrinogen ◽  
Carboxypeptidase B ◽  
Immunochemical Detection ◽  
Proteins And Peptides

Abstract The immunochemical specificity of rabbit antisera to human fibrinopeptide-B (FPB) has been studied by comparing the relative abilities of FPB and of various proteins and peptides containing the NH2-terminal segment of the B beta-chain of human fibrinogen to inhibit the binding of a radioiodinated FPB derivative by each of seven anti- FPB sera. Anti-FBP sera varied in the extent to which they cross- reacted with fibrinogen, the NH2-terminal disulfide knot of fibrinogen (N-DSK), B beta 1(Pyr)-118(Met), B beta 1(Pyr)-42(Arg), and desarginyl- FPB. Anti-FPB sera have been identified that discriminate effectively between FPB and larger FBP-containing peptides; such antisera can be used to measure FPB in the absence of the larger peptides or to demonstrate the presence of larger peptides such as B beta 1(Pyr)- 42(Arg) in extracts of clinical plasma samples by means of an increase in FPB immunoreactivity following thrombin treatment. One anti-FPB serum has been identified that is capable of detecting desarginyl-FPB, and this antiserum has been used in the development of a radioimmunoassay for desarginyl-FPB. Thus, by precisely defining the specificity of anti-FPB sera, it has been possible to identify antisera that are useful, not only in the measurement of FPB, but also in the detection of other important related molecules, such as B beta 1(Pyr)- 42(Arg) and desarginyl-FPB. The immunochemical detection of these FPB- related peptides should provide useful information concerning the action of proteolytic enzymes, such as plasmin on the NH2-terminal segment of the B beta-chain of fibrinogen, and of carboxypeptidase-B on free FPB, in human plasma.

The ubiquitin–proteasome system and skeletal muscle wasting

2005 ◽  
Vol 41 ◽  
pp. 173-186 ◽  
Author(s):  
Didier Attaix ◽  
Sophie Ventadour ◽  
Audrey Codran ◽  
Daniel Béchet ◽  
Daniel Taillandier ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Wasting ◽  
Proteolytic Enzymes ◽  
Cathepsin L ◽  
Ubiquitin Proteasome System ◽  
Complete Breakdown ◽  
Skeletal Muscle Proteins ◽  
Ubiquitin Proteasome ◽  
Tripeptidyl Peptidase Ii ◽  
F Box Protein

The ubiquitin–proteasome system (UPS) is believed to degrade the major contractile skeletal muscle proteins and plays a major role in muscle wasting. Different and multiple events in the ubiquitination, deubiquitination and proteolytic machineries are responsible for the activation of the system and subsequent muscle wasting. However, other proteolytic enzymes act upstream (possibly m-calpain, cathepsin L, and/or caspase 3) and downstream (tripeptidyl-peptidase II and aminopeptidases) of the UPS, for the complete breakdown of the myofibrillar proteins into free amino acids. Recent studies have identified a few critical proteins that seem necessary for muscle wasting {i.e. the MAFbx (muscle atrophy F-box protein, also called atrogin-1) and MuRF-1 [muscle-specific RING (really interesting new gene) finger 1] ubiquitin–protein ligases}. The characterization of their signalling pathways is leading to new pharmacological approaches that can be useful to block or partially prevent muscle wasting in human patients.

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