Covalent Modification of the Amine Transporter with N,N′-Dicyclohexylcarbodiimide

Raul Suchi, Yael Stern-Bach, Tal Gabay, Shimon Schuldiner*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

N,N′-Dicyclohexylcarbodiimide (DCC) has been previously shown to inhibit the amine transporter from chromaffin granules [Gasnier, B., Scherman, D., & Henry, J. P. (1985) Biochemisty 24, 3660-3667]. A study of the mechanism of inhibition is presented together with the demonstration of covalent modification of the protein. DCC inhibits binding of R1 (reserpine) and R2 (tetrabenazine) types of ligands to the transporter as well as transport. Ligands of the R2 type, but not those of the R1 type, protect against inhibition of all the reactions by DCC, i.e., accumulation of serotonin, binding if reserpine (R1 ligand), and binding of ketanserine (R2 ligand). The ability of a given R2 ligand to protect the transporter correlates well with its binding constant. Water-soluble carbodiimides, such as l-ethyl-3-[3-(diethylamino)propyl]carbodiimide (EDC), do not have any effect on the catalytic activity of the transporter. A fluorescent hydrophobic analogue of DCC, N-cyclohexyl-N′-[4-(dimethylamino)-α-naphthyl]carbodiimide (NCD-4), inhibits at about the same concentration range as DCC. [14C]DCC labels several polypeptides in the chromaffin granule membranes. Labeling of a polypeptide with an apparent Mr of 80K is inhibited in the presence of R2 ligands. The labeled polypeptide copurifies with the recently identified and isolated transporter [Stern-Bach, Y., Greenberg-Ofrath, N., Flechner, I., & Schuldiner, S. (1990) J. Biol. Chem. 256, 3961-3966].

Original languageAmerican English
Pages (from-to)6490-6494
Number of pages5
JournalBiochemistry
Volume30
Issue number26
DOIs
StatePublished - 1 Jul 1991

Fingerprint

Dive into the research topics of 'Covalent Modification of the Amine Transporter with N,N′-Dicyclohexylcarbodiimide'. Together they form a unique fingerprint.

Cite this