Biomaterial Database

Structure-activity relationship of C-terminal hexa- and heptapeptide substance P antagonists as studied in the guinea-pig ileum. 1984

J Hörig, and H Schultheiss

The 14 C-terminal heptapeptide analogues and one hexapeptide analogue of substance P (SP) were synthesized on the basis of the SP antagonist [D-Pro2,D-Trp7,9]SP-(1-11). They were tested in the guinea-pig ileum preparation for spasmogenic and antagonistic activities. All analogues except two had antagonistic activity. Spasmogenic activity was observed in three heptapeptide SP antagonists: [Arg5,D-Trp7,D-pCl-Phe9]SP-(5-11), [Arg5,D-Trp7,9,p-Cl-Phe8]SP-(5-11) and [Arg5,D-Trp7,9,Nle11]SP-(5-11). However, this effect became greatly reduced upon successive applications in almost all ileum preparations. For antagonistic potency D-Trp turned out to be of greater importance in position 9 than in position 7 of the SP molecule. The presence of a free amino group at the N-terminal of the peptide was also of significant importance for antagonistic potency. Exchange of Met11 for Nle resulted in a considerable increase of antagonistic potency, while other substitutions in this position were ineffective or slightly reduced the antagonistic effect in the ileum preparation.

UI	MeSH Term	Description	Entries
D007082	Ileum	The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
D009119	Muscle Contraction	A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments.	Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
D009130	Muscle, Smooth	Unstriated and unstriped muscle, one of the muscles of the internal organs, blood vessels, hair follicles, etc. Contractile elements are elongated, usually spindle-shaped cells with centrally located nuclei. Smooth muscle fibers are bound together into sheets or bundles by reticular fibers and frequently elastic nets are also abundant. (From Stedman, 25th ed)	Muscle, Involuntary,Smooth Muscle,Involuntary Muscle,Involuntary Muscles,Muscles, Involuntary,Muscles, Smooth,Smooth Muscles
D010446	Peptide Fragments	Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.	Peptide Fragment,Fragment, Peptide,Fragments, Peptide
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000595	Amino Acid Sequence	The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.	Protein Structure, Primary,Amino Acid Sequences,Sequence, Amino Acid,Sequences, Amino Acid,Primary Protein Structure,Primary Protein Structures,Protein Structures, Primary,Structure, Primary Protein,Structures, Primary Protein
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D013373	Substance P	An eleven-amino acid neurotransmitter that appears in both the central and peripheral nervous systems. It is involved in transmission of PAIN, causes rapid contractions of the gastrointestinal smooth muscle, and modulates inflammatory and immune responses.	Euler-Gaddum Substance P,Hypothalamic Substance P,SP(1-11),Euler Gaddum Substance P,Substance P, Euler-Gaddum,Substance P, Hypothalamic
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In