title: A selective biotinylated probe for V1a vasopressin receptors.
abstract: We have designed and synthesized a biotinylated vasopressin antagonist which is a selective probe for studying the V1a subtype of vasopressin receptor. Initially we synthesized the novel vasopressin analogue d(CH2)5Tyr(Me)2LysNH2(9)AVP (ALVP). Biotinamidocaproate was subsequently coupled to the epsilon-amino group of ALVP to generate the novel biotinylated probe d(CH2)5Tyr(Me)2Lys(N epsilon-biotinamido-caproate)NH2(9)AVP (ALBtnVP). Pharmacological characterization of ALVP and ALBtnVP established that both ligands were high affinity antagonists at V1a receptors, and that both displayed marked V1a/V2 selectivity. The observation that receptor-bound ALBtnVP was bi-functional, and thereby able to bind conjugated derivatives of avidin or streptavidin, allowed ALBtnVP to be utilized as a selective probe for V1a receptors. This strategy allowed the visualization of V1a receptors on the surface of WRK-1 cells and hippocampal neurons, by using streptavidin-gold with electron microscopy and fluorescein-avidin with light microscopy. We conclude that ALBtnVP is a useful probe for V1a receptors.
authors.affiliation: School of Biochemistry, University of Birmingham, Edgbaston, U.K.
authors.forename: J
authors.initials: J
authors.lastname: Howl
authors.forename: I D
authors.initials: ID
authors.lastname: Kerr
authors.forename: C H
authors.initials: CH
authors.lastname: Chan
authors.forename: M
authors.initials: M
authors.lastname: Wheatley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001127:Arginine Vasopressin / Q000031:analogs & derivatives; D001360:Avidin; D001426:Bacterial Proteins; D001710:Biotin; D002460:Cell Line; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006624:Hippocampus / Q000737:chemistry; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D015335:Molecular Probes; D008969:Molecular Sequence Data; D015394:Molecular Structure; D051381:Rats; D011919:Rats, Inbred Strains; D011945:Receptors, Angiotensin / Q000032:analysis*; D017483:Receptors, Vasopressin; D019809:Streptavidin; D014667:Vasopressins / Q000037:antagonists & inhibitors
chemical_list: D001426:Bacterial Proteins; D015335:Molecular Probes; D011945:Receptors, Angiotensin; D017483:Receptors, Vasopressin; D014667:Vasopressins; D001127:Arginine Vasopressin; C070817:argipressin, beta-mercapto-beta, beta-cyclopentamethylenepropionic acid(1)-O-methyl-Tyr(2)-LysNH2(9)-; D001360:Avidin; D001710:Biotin; D019809:Streptavidin