Related Experiment Videos
Isolation and sequence determination of frog C-type natriuretic peptide
A Yoshihara1, H Kozawa, N Minamino
1Department of Biochemistry, Miyazaki Medical College, Japan.
Biochemical and Biophysical Research Communications
|December 14, 1990
Summary
Researchers discovered a new frog C-type natriuretic peptide (CNP) from frog brains. This peptide regulates body fluid balance and lowers blood pressure in rats, similar to porcine CNP.
Area of Science:
- Biochemistry
- Neuroendocrinology
- Comparative Physiology
Background:
- Natriuretic peptides are crucial regulators of cardiovascular and renal functions.
- The C-type natriuretic peptide (CNP) family has been identified in various species, playing roles in vasodilation and fluid balance.
- The central nervous system's role in regulating body fluid homeostasis is complex and involves various signaling molecules.
Purpose of the Study:
- To isolate and characterize a novel bioactive peptide from the frog brain.
- To determine the amino acid sequence and structural classification of the isolated peptide.
- To investigate the physiological activities, including diuretic-natriuretic and hypotensive effects, of the novel peptide.
Main Methods:
- Bioassay-guided isolation of the peptide from frog brain extract using chick rectum relaxant activity.
- Amino acid sequencing to determine the peptide's primary structure.
- Administration of the purified peptide to rats to assess its physiological effects (diuretic, natriuretic, hypotensive).
- Comparative analysis of the peptide's structure and function with known natriuretic peptides.
Main Results:
- A novel bioactive peptide was successfully isolated from the frog brain.
- The peptide's amino acid sequence was determined as Gly-Tyr-Ser-Arg-Gly-Cys-Phe-Gly-Val-Lys-Leu-Asp-Arg-Ile-Gly-Ala-Phe-Ser-Gly-Leu-Gly-Cys, with a disulfide bond between two cysteine residues.
- The isolated peptide exhibited significant diuretic-natriuretic and hypotensive activities in rats.
- Structural and pharmacological similarities were observed between the novel peptide and porcine C-type natriuretic peptide (CNP).
Conclusions:
- The novel peptide was designated as frog C-type natriuretic peptide (frog CNP) due to its structural and functional resemblance to porcine CNP.
- Frog CNP likely plays a role in the central regulation of body fluid homeostasis, given its high concentration in the brain.
- This discovery expands our understanding of natriuretic peptide diversity and their physiological roles across species.