6. Affinity Labels and Marker Groups for MSH

2015 ◽  
pp. 79-87
Keyword(s):  
Affinity Labels

Opium Alkaloids and Affinity Labels

1990 ◽  
Author(s):  
Sydney Archer ◽  
Jean Bidlack ◽  
G. Keith Mulhollund
Keyword(s):  
Affinity Labels ◽  
Opium Alkaloids

Synthesis of Cryptophycin Affinity Labels and Tubulin Labeling

2004 ◽  
Author(s):  
Kyounglang Yang ◽  
AGunda I. Georg
Keyword(s):  
Affinity Labels

Synthesis of Cryptophycin Affinity Labels and Tubulin Labeling

2005 ◽  
Author(s):  
KyoungLang Yang ◽  
Gunda I. Georg
Keyword(s):  
Affinity Labels

The melanocyte stimulating activity of N-nitroso-2-chloroethyl-carbamoyl derivatives of α-melanotropin fragments

1988 ◽  
Vol 53 (11) ◽  
pp. 2574-2582 ◽  
Author(s):  
Hedvig Medzihradszky-Schweiger ◽  
Helga Süli-Vargha ◽  
József Bódi ◽  
Kálmán Medzihradszky
Keyword(s):  
Biological Activity ◽  
Active Site ◽  
Frog Skin ◽  
Terminal Sequence ◽  
Subsequent Reaction ◽  
Affinity Labels ◽  
Derivatives Of

A number of N-nitroso-2-chloroethyl-carbamoyl (Q(NO)) derivatives of α-melanotropin fragments have been synthesized and their effect on the frog skin melanocytes studied. Peptides substituted in this way possess the biological activity of the parent compounds, indicating that they preserved their receptor recognizing ability. These compounds can therefore serve as affinity labels. Some of these derivatives, related to the C-terminal sequence of α-melanotropin show prolonged darkening reaction, which does not influence the subsequent reaction of melanocytes with α-melanotropin. The Q(NO)-derivative of a fragment derived from the classical active site of the hormone shows, however, inhibition of the effect of α-melanotropin. It can be concluded that the latter peptide acts through the melanotropin receptor, while others, related to the C-terminal sequence of the hormone through another mechanism.

scholarly journals Metal-Conjugated Affinity Labels: A New Concept to Create Enantioselective Artificial Metalloenzymes

ChemistryOpen ◽  
2013 ◽  
Vol 2 (2) ◽  
pp. 50-54 ◽  
Author(s):  
Thomas Reiner ◽  
Dominik Jantke ◽  
Alexander N. Marziale ◽  
Andreas Raba ◽  
Jörg Eppinger
Keyword(s):  
Affinity Labels ◽  
Artificial Metalloenzymes

scholarly journals Cover Picture: Metal-Conjugated Affinity Labels: A New Concept to Create Enantioselective Artificial Metalloenzymes (ChemistryOpen 2/2013)

ChemistryOpen ◽  
2013 ◽  
Vol 2 (2) ◽  
pp. 39-39
Author(s):  
Thomas Reiner ◽  
Dominik Jantke ◽  
Alexander N. Marziale ◽  
Andreas Raba ◽  
Jörg Eppinger
Keyword(s):  
Affinity Labels ◽  
Artificial Metalloenzymes

scholarly journals Chemical Modification of the Active Site of the Acetylcholine Receptor

1969 ◽  
Vol 54 (1) ◽  
pp. 245-264 ◽  
Author(s):  
Arthur Karlin
Keyword(s):  
Chemical Modification ◽  
Acetylcholine Receptor ◽  
Disulfide Bond ◽  
Active Site ◽  
Quaternary Ammonium ◽  
Competitive Inhibitor ◽  
Affinity Labels ◽  
Electrophorus Electricus ◽  
Depolarizing Agents ◽  
Monoquaternary Ammonium

The receptor for acetylcholine in the subsynaptic membrane of the electroplax of Electrophorus electricus is a protein with a disulfide bond in the vicinity of the active site. This disulfide can be reduced and reoxidized with concomitant inhibition and restoration of the response to acetylcholine and other monoquaternary ammonium-depolarizing agents. Conversely, the bisquaternary hexamethonium, normally a competitive inhibitor, causes depolarization, and the activity of decamethonium is increased following reduction of the disulfide. The reduced receptor can be alkylated by various maleimide derivatives and is then no longer reoxidizable. Some quaternary ammonium maleimide derivatives act as affinity labels of the reduced receptor, alkylating it at a rate three orders of magnitude faster then do uncharged maleimide derivatives. Other types of potential affinity labels also react only with the reduced receptor and the resulting covalently attached quaternary ammonium moieties interact with the active site, strongly activating the receptor. These results suggest a model for the active site and its transitions in which an activator such as acetylcholine bridges between a negative subsite and a hydrophobic subsite in the vicinity of the disulfide, causing an altered conformation around the negative subsite and a decrasee of a few angstroms in the distance between the two subsites.

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