Several peptides associated with feeding behavior have been reported recently. Orexins (Orexin-A and Orexin-B) are a family of hypothalamic neuropeptides selectively expressed in the hypothalamus (1). Orexin-A and Orexin-B are derived from the same precursor (Prepro-orexin) by proteolytic cleavage. Prepro-orexin is 130 amino acid long peptide with a putative 33 AA secretory sequence, a hydrophobic core followed by residues with small polar side chains. Orexins are also described as hypocretins.

The mature Orexin-A is a 33-aa peptide (mol. Wt. 3562 Da), with an N-terminal pyrogutalmyl residue and C-terminal amide. It has 2 disulfide bonds: Cys6-12 and Cys7-14. Human, bovine, mouse, and rat Orexin-A are identical. Orexin-B is a 28 AA polypeptide with C-terminal amide (mol. Wt 2937). Orexin-B shares 46% identity with Orexin-A (13/28 AA). Orexin expression was detected in brain and to a small extent in testis (1). These neuropeptides bind and activate two closely related Orexin receptors--G-protein coupled receptors (GPCRs) OX1R (rat 416 AA, Human 425 aa) and OX2R (rat 460 aa; human 444 aa). Northern blots reveal OX1R and OX2R expression exclusively in the brain (1).

Orexin-A <EPL PDC* C*RQ KTC* SC*R LYE LLH GAG NHA AGI LTL-Amide; 33 AA
(Cys6-Cys-12; Cys7-Cys14); <E=Pyroglutamyl residue.

. ...h Orexins-B, RSG PPG LQG RLQ RLL QAS GNH AAG ILT M-Amide; 28 aa
m/r Orexins-B, . RPG PPG LQG RLQ RLL QAN GNH AAG ILT M-Amide; 28 aa

Orexin expression was detected in brain and to a small extent in testis (1). These neuropeptides bind and activate two closely related Orexin receptors--G-protein coupled receptors (GPCRs) OX1R and OX2R. Northern blots reveal OX1R and OX2R expression exclusively in the brain (1).

ADI has produced anti pre-pro-orexin, Orexin-A & B and Orexin receptor antibodies using a specific peptide sequences. The control peptides were used to affinity purify the antibodies. The appropriate control immunogenic peptides are also available to confirm specificity of antibodies. Availability of these immuno-reagents will contribute to the understanding of feeding behavior and help cure obesity related diseases.

M= Mouse; R=Rat; H=Human; Ha=Hamster; Rb=Rabbit; B=Bovine; ; CT= near C-terminus; NT=near N-terminus; EC=Extracellular domain; CP (Cytoplasmic domain)

** Human and Mouse Orexin-A & B available in 1 mg, 10 mg, 50 mg, 100 mg sizes.

** Expected antibody crossreactivity information is mostly based upon high (>70%) sequence conservation of antigenic/control peptides in various species. When antibody crossreactivity has actually been experimentally confirmed in various species, it will be mentioned in the appropriate data sheets.

"Neat Antisera" are the unpurified antiserum and it is suitable for ELISA and Western.
"Affinity pure" IgG may be more suitable for immunohistochemical (IHC) applications and to reduce background in most immunological applications including ELISA and Western.
"Control peptides" can not be used for Western as they are very short peptides. They are intended for ELISA or antibody blocking studies to establish antibody specificity.

All Products are for in vitro research use only. 40512A

Citations of ADI's Antibodies to Orexins and Orexin receptors &b Biological effects of ADI's Orexins

Anti-OX1R
Irving EA et al, Increased cortical expression of the orexin-1 receptor following permanent middle cerebral artery occlusion in the rat (2002) Neuroscience Lett. in press WB, IHC (rat brain, 4% PF)

Naslun E et al, (2002), Localization and effects of orexin on fasting motility in the rat duodenum, Am J Physiol Gastrointest Liver Physiol 282: G470-G479, IHC (rat duodenum)

Montserrat Blanco, Miguel López, Tomás GarcÍa-Caballero, RosalÍa Gallego, Ángel Vázquez-Boquete, Gerard Morel, Rosa SeñarÍs, Felipe Casanueva, Carlos Diéguez, and Andrés Beiras (2001) Cellular Localization of Orexin Receptors in Human Pituitary, J. Clin. Endocrinol. Metab. 86: 3444-3447, IHC

S. Bingham, a, P. T. Daveya, A. J. Babbsa, E. A. Irvinga, M. J. Sammonsa, M. Wylesa, P. Jeffreyb, L. Cutlerb, I. Ribab, A. Johnsc, R. A. Porterc, N. Uptona, A. J. Huntera and A. A. Parsons (2001) Orexin-A, an hypothalamic peptide with analgesic properties, Pain 2, 81-90, IHC (PF-fixed, slide mounted and free floating)

Kirchgessner, Kirchgessner (1999) Orexin Synthesis and Response in the Gut Neuron 24: 941-951, IHC

Blanco M et al (2001) Cellular Localization of orexin receptors in human pituitary, J Clin. Endocrinol. Metabol. 86, 1616-1619, IHC (antigen retrieval by pressure cooking)

Lopez M et al (1999) Orexin receptors are expressed in the adrenal medulla of the rat Endocrinol. 140, 5991-5994, IHC

Montserrat Blancoa, Tomás García-Caballeroa, Máximo Fragab, Rosalía Gallegoa, Juan Cuevasa, Jerónimo Fortezab, Andrés Beirasa and Carlos Diéguez (2001) Cellular localization of orexin receptors in human adrenal gland, adrenocortical adenomas and pheochromocytomas, Regulaotry Peptide 2001 in press, IHC (formaldehyde, paraffin embedded sections)'

Naslun E et al 2002 Localization and effects of orexin on fasting motility in the rat duodenum Am J Physiol Gastrointest Liver Physiol 282: G470-G479, IHC (rat duodenum)

Anti-OX2R
Lopez M et al 1999 Orexin receptors are expressed in the adrenal medulla of the rat Endocrinol. 140, 5991-5994, IHC

Blanco M et al 2001 Cellular Localization of orexin receptors in human pituitary J Clin. Endocrinol. Metabol. 86, 1616-1619, IHC (antigen retrieval by pressure cooking)

Montserrat Blanco, Miguel López, Tomás GarcÍa-Caballero, RosalÍa Gallego, Ángel Vázquez-Boquete, Gerard Morel, Rosa SeñarÍs, Felipe Casanueva, Carlos Diéguez, and Andrés Beiras 2001 Cellular Localization of Orexin Receptors in Human Pituitary J. Clin. Endocrinol. Metab. 2001 86: 3444-3447, IHC

Montserrat Blancoa, Tomás García-Caballeroa, , , Máximo Fragab, Rosalía Gallegoa, Juan Cuevasa, Jerónimo Fortezab, Andrés Beirasa and Carlos Diéguez 2001, Cellular localization of orexin receptors in human adrenal gland, adrenocortical adenomas and pheochromocytomas, Regulaotry Peptide 2001 in press, IHC (formaldehyde, paraffin)

Kirchgessner, Kirchgessner 1999 Orexin Synthesis and Response in the Gut Neuron 24: 941-951, IHC

Orexins-A and Orexins-B

OX-A
Dube MG 2000 Evidence of NPY Y5 receptor involvement in food intake elicited by orexin A in sated rats Peptides, 21, 1557-1560, ADI's Orexin-A, Feeding, biological effect

Dube MG 1999 Food intake elicited by central administration of orexins/hypocretins:identificaiton of hypothalamus sites of actions Brain Res. 842, 473-477, ADI's Orexin-A feeding biological effect

Jain, Mukul R 2000 Evidence that NPY Y1 receptors are involved in stimulation of feeding by orexins sated rats Regulatory Peptides, 87, 19-24, ADI's Orexin-A feeding biological effect

Anti Orexin-A

Kirchgessner, Kirchgessner 1999 Orexin Synthesis and Response in the Gut Neuron 24: 941-951, IHC Stomach and Intestine

Naslun E et al 2002 Localization and effects of orexin on fasting motility in the rat duodenum Am J Physiol Gastrointest Liver Physiol 282: G470-G479, IHC (rat duodenum)

Zbigniew K Krowicki, Melissa A Burmeister, Hans-Rudolf Berthoud, Roisin T Scullion, Kristine Fuchs, and Pamela J Hornby 2002 OREXINS IN RAT DORSAL MOTOR NUCLEUS OF THE VAGUS POTENTLY STIMULATE GASTRIC MOTOR FUNCTION Am J Physiol Cell Physiol 2001 in press, IHC rat brain