Biomaterial Database

Cholesterol side-chain cleavage in the rat adrenal cortex: isolation of a cycloheximide-sensitive activator peptide. 1983

R C Pedersen, and A C Brownie

A cytosolic peptide activator (Mr approximately equal to 2,200) of cholesterol side-chain cleavage in the adrenal cortex has been isolated from normal corticotropin-treated rats and from rats implanted with the MtT/F4 corticotropin-secreting pituitary tumor. The isolation techniques were those common to peptide hormone purification, including tissue extraction into a highly acidic medium, gel filtration, and reverse-phase HPLC. The amino acid composition has been determined on acid hydrolysates. The activity of this adrenal peptide is acutely increased in hypophysectomized animals treated with corticotropin, and this increase is blocked by cycloheximide. The addition of activator peptide to adrenal mitochondrial preparations results in a rapid stimulation of pregnenolone formation that is dependent on activator concentration and a source of NADPH. In the absence of NADPH, addition of activator peptide to adrenal mitochondria increases the rate of cholesterol association with side-chain cleavage cytochrome P-450. The peptide therefore exhibits properties that are believed to characterize the hypothetical corticotropin-dependent labile activator of adrenal steroidogenesis.

UI	MeSH Term	Description	Entries
D007526	Isoelectric Point	The pH in solutions of proteins and related compounds at which the dipolar ions are at a maximum.	Isoelectric Points,Point, Isoelectric,Points, Isoelectric
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D002784	Cholesterol	The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.	Epicholesterol
D003513	Cycloheximide	Antibiotic substance isolated from streptomycin-producing strains of Streptomyces griseus. It acts by inhibiting elongation during protein synthesis.	Actidione,Cicloheximide
D003600	Cytosol	Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.	Cytosols
D005260	Female		Females
D000302	Adrenal Cortex	The outer layer of the adrenal gland. It is derived from MESODERM and comprised of three zones (outer ZONA GLOMERULOSA, middle ZONA FASCICULATA, and inner ZONA RETICULARIS) with each producing various steroids preferentially, such as ALDOSTERONE; HYDROCORTISONE; DEHYDROEPIANDROSTERONE; and ANDROSTENEDIONE. Adrenal cortex function is regulated by pituitary ADRENOCORTICOTROPIN.	Cortex, Adrenal
D000324	Adrenocorticotropic Hormone	An anterior pituitary hormone that stimulates the ADRENAL CORTEX and its production of CORTICOSTEROIDS. ACTH is a 39-amino acid polypeptide of which the N-terminal 24-amino acid segment is identical in all species and contains the adrenocorticotrophic activity. Upon further tissue-specific processing, ACTH can yield ALPHA-MSH and corticotrophin-like intermediate lobe peptide (CLIP).	ACTH,Adrenocorticotropin,Corticotropin,1-39 ACTH,ACTH (1-39),Adrenocorticotrophic Hormone,Corticotrophin,Corticotrophin (1-39),Corticotropin (1-39),Hormone, Adrenocorticotrophic,Hormone, Adrenocorticotropic
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
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus