Biokimia Hormon
Susila Sastri
Hormon
• Hormone : chemical entity that is secreted
or produced by specific glands or cells
and that acts as a chemical messenger or
signal molecule
• Hormones circulate as signaling substances
in the blood at very low concentrations (10–
12 to between 10–7 mol L–1).
The four primary areas
of hormone action
Growth &
Development
Reproduction
Hormones
Maintenance of
internal
environment
Energy production,
utilization &
storage
Cell Communication
GAS MOLECULE
Generalized Signal Transduction Pathway
Simple Intracellular & Extracelluler
Signaling
Receptor
Receptors: specific membrane proteins,
which are able to recognize and bind to
corresponding ligand molecules,
become activated, and transduce signal
to next signaling molecules:
A. Membran
B. Intra Sel
Glycoprotein or Lipoprotein
Properties of binding of Hormon
and Receptor
• highly specificity
• highly affinity
• saturation
• reversible binding
• special function model
Control of receptor activity
• Phosphorylation or
dephosphorylation of R
• Phospholipid of membrane
• Enzyme catalyzed hydrolysis
• G protein regulation
Function of receptor
(1) Recognize the special ligand
(2) Binding to special ligand
(3) Signal transduction
biological effect
Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
Hypothalamus
Releasing
hormones
Anterior pituitary
Nervous
Posterior pituitary
Thyrotropin
Somatotropin
FSH
Vasopressin
Prolactin
LH
Oxytocin
ACTH
Adrenal
Thyroid Cortex Pancreas Ovary
T3
Testis
Cortisol
Insulin,
Estradiol Testosterone
aldosterone glucagon,
somatostatin
Muscles
liver
Tissues
Liver,
muscles
Adrenal
Medulla
Epinephrine
Reproductive Mammary
organs
glands
Struktur Kimia Hormon
1. Derived from amino acids (Hydrophilic)
Amino acid derivatives thyroxine
Histamine, serotonin, melatonin, and the
catecholamines, dopa, dopamine,
norepinephrine, and epinephrine are
known as “biogenic amines.”
Tripeptides
TRH
Small peptides
VP (ADH), somatostatin
Intermediate-size
insulin, parathyroid hormone
peptides
Complex polypeptides gonadotropins, TSH
and glycoproteins
A. Signaling substances derived from amino acids
B. Examples of peptide hormones and proteohormones
2. Derived from lipid precursors
Cholesterol derivatives
cortisol, testosterone, vitamin D ,
estradiol
Fatty acid derivatives prostaglandins, leukotrienes
Phospholipid derivative platelet-activating factor
Lipophilic hormones
Steroid hormones
Calcitriol (vitamin D hormone) is also included in this group, although it has a modified
steroid structure.The most important steroid hormone in invertebrates is ecdysone.
3. Derived from other chemicals (mediator)
adenosine
Purines
nitric oxide
Gases
Pituitary hormones and the hypothalamic
factors controlling their secretion
Classification of hormones: mechanism
of action.
• Hormones that bind to intracellular receptors
• Hormones that bind to cell surface receptors
– The second messenger is cAMP
– The second messenger is cGMP
• The second messenger : calcium or
phosphatidylinositols (or both)
• The second messenger : a kinase or
phosphatase cascade
I. Hormones that bind to intracellular receptors
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Androgens
Calcitriol (1,25[OH]2-D3)
Estrogens
Glucocorticoids
Mineralocorticoids
Progestins
Retinoic acid
Thyroid hormones (T3 and T4)
II. Hormones that bind to cell surface receptors
A. The second messenger is
cAMP:
B. The second messenger is
cGMP:
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α2-Adrenergic catecholamines
β-Adrenergic catecholamines
Adrenocorticotropic hormone
Antidiuretic hormone
Calcitonin
Chorionic gonadotropin, human
Corticotropin-releasing hormone
Follicle-stimulating hormone
Glucagon
Lipotropin
Luteinizing hormone
Melanocyte-stimulating hormone
Parathyroid hormone
Somatostatin
Thyroid-stimulating hormone
Atrial natriuretic factor
Nitric oxide
II. Hormones that …..
C. The second messenger is calcium or
phosphatidylinositols (or both):
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Acetylcholine (muscarinic)
α1-Adrenergic catecholamines
Angiotensin II
Antidiuretic hormone
(vasopressin)
Cholecystokinin
Gastrin
Gonadotropin-releasing
hormone
Oxytocin
Platelet-derived growth factor
Substance P
Thyrotropin-releasing hormone
D. The second messenger is a kinase
or phosphatase cascade:
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Chorionic somatomammotropin
Epidermal growth factor
Erythropoietin
Fibroblast growth factor
Growth hormone
Insulin
Insulin-like growth factors I and II
Nerve growth factor
Platelet-derived growth factor
Prolactin