FMRFamide receptors of Helix aspersa

Miscellaneous · Fri Jan 01 00:00:00 EST 1988

OSTI ID:7245947

Payza, K

A receptor binding assay and an isolated heart bioassay were used to identify and characterize the FMRFamide receptors in Helix. In the heart bioassay, FMRFamide increased myocardial contraction force. A potent FMRFamide analog, desaminoTyr-Phe-norLeu-arg-Phe-amide (daYFnLRFamide), was used as a radioiodinated receptor ligand. The high affinity binding of {sup 125}I-daYFnLRFamide at 0{degree}C to Helix brain membranes was reversible, saturable, pH-dependent and specific, with a K{sub D} of 13-14 nM. A lower affinity (245 nM) site was also observed. Radioligand binding sites were also identified in the heart, male reproductive organs and digestive organs. The structure-activity relations (SAR) of cardiostimulation correlated with the specificity of {sup 125}I-daYFnLRFamide binding to brain and heart receptors. The SAR were similar to those of other molluscan FMRFamide bioassays, except that they showed a marked preference for some analogs with blocked amino-terminals.

• Research Organization: Florida Univ., Gainesville, FL (USA)
• OSTI ID: 7245947
• Resource Relation: Other Information: Thesis (Ph. D.)
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MOLLUSCS
BIOCHEMISTRY
PEPTIDES
RECEPTORS
CHEMICAL COMPOSITION
BIOCHEMICAL REACTION KINETICS
CELL MEMBRANES
HEART
IODINE 125
SPECIFICITY
STRUCTURE-ACTIVITY RELATIONSHIPS
TRACER TECHNIQUES
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR SYSTEM
CELL CONSTITUENTS
CHEMISTRY
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
INVERTEBRATES
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MEMBRANE PROTEINS
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPES
REACTION KINETICS
550201* - Biochemistry- Tracer Techniques