Properties of tyrosine hydroxylation in living mouse neuroblastoma clone N1E 115

E. Richelson

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

Tyrosine hydroxylation was studied in intact cells of mouse neuroblastoma clone N1E 115 which have high levels of tyrosine 3 monooxygenase and which have been fully characterized for tyrosine transport. Measurement of [3H]OH formed from L [3,5 3H]tyrosine in the medium was the method of assay and [3H]OH formed was stoichiometric with the formation of L [3H]3,4 dihydroxyphenylalanine. Tyrosine hydroxylation was dependent on time of incubation, cell number, and the concentration of [3H]tyrosine in the medium. From velocity vs. [3H]tyrosine concentration experiments, two apparent K(m) values were obtained: K(m1) = 10 ± 2 μM; K(m2) = 140 ± 10 μM. Substrate inhibition occurred with tyrosine concentrations between 20 and 50 μM. The reaction was twice as fast at pH 5.5 as at pH 7.4. α,α' Dipyridyl (1 mM) caused major inhibition (75%) when [3H]tyrosine concentration was 10 μM. L 3 Iodotyrosine was a competitive inhibitor with K(i) = 0.3 μM. Dopamine was a noncompetitive inhibitor with K(i) = 500 μM. 1 Norepinephrine had no effect. These results show that the hydroxylation of tyrosine by living N1E 115 cells has many of the properties of the reaction catalyzed by purified tyrosine 3 monooxygenase from normal tissue.

Original languageEnglish (US)
Pages (from-to)1113-1118
Number of pages6
JournalJournal of Neurochemistry
Volume27
Issue number5
StatePublished - 1976

Fingerprint

Hydroxylation
Neuroblastoma
Tyrosine
Clone Cells
Tyrosine 3-Monooxygenase
Dihydroxyphenylalanine
Levodopa
Assays
Dopamine
Norepinephrine
Cell Count
Cells
Tissue

ASJC Scopus subject areas

  • Biochemistry
  • Cellular and Molecular Neuroscience

Cite this

Properties of tyrosine hydroxylation in living mouse neuroblastoma clone N1E 115. / Richelson, E.

In: Journal of Neurochemistry, Vol. 27, No. 5, 1976, p. 1113-1118.

Research output: Contribution to journalArticle

@article{ea63606636934a8d9f36e204a7b79fa4,
title = "Properties of tyrosine hydroxylation in living mouse neuroblastoma clone N1E 115",
abstract = "Tyrosine hydroxylation was studied in intact cells of mouse neuroblastoma clone N1E 115 which have high levels of tyrosine 3 monooxygenase and which have been fully characterized for tyrosine transport. Measurement of [3H]OH formed from L [3,5 3H]tyrosine in the medium was the method of assay and [3H]OH formed was stoichiometric with the formation of L [3H]3,4 dihydroxyphenylalanine. Tyrosine hydroxylation was dependent on time of incubation, cell number, and the concentration of [3H]tyrosine in the medium. From velocity vs. [3H]tyrosine concentration experiments, two apparent K(m) values were obtained: K(m1) = 10 ± 2 μM; K(m2) = 140 ± 10 μM. Substrate inhibition occurred with tyrosine concentrations between 20 and 50 μM. The reaction was twice as fast at pH 5.5 as at pH 7.4. α,α' Dipyridyl (1 mM) caused major inhibition (75{\%}) when [3H]tyrosine concentration was 10 μM. L 3 Iodotyrosine was a competitive inhibitor with K(i) = 0.3 μM. Dopamine was a noncompetitive inhibitor with K(i) = 500 μM. 1 Norepinephrine had no effect. These results show that the hydroxylation of tyrosine by living N1E 115 cells has many of the properties of the reaction catalyzed by purified tyrosine 3 monooxygenase from normal tissue.",
author = "E. Richelson",
year = "1976",
language = "English (US)",
volume = "27",
pages = "1113--1118",
journal = "Journal of Neurochemistry",
issn = "0022-3042",
publisher = "Wiley-Blackwell",
number = "5",

}

TY - JOUR

T1 - Properties of tyrosine hydroxylation in living mouse neuroblastoma clone N1E 115

AU - Richelson, E.

PY - 1976

Y1 - 1976

N2 - Tyrosine hydroxylation was studied in intact cells of mouse neuroblastoma clone N1E 115 which have high levels of tyrosine 3 monooxygenase and which have been fully characterized for tyrosine transport. Measurement of [3H]OH formed from L [3,5 3H]tyrosine in the medium was the method of assay and [3H]OH formed was stoichiometric with the formation of L [3H]3,4 dihydroxyphenylalanine. Tyrosine hydroxylation was dependent on time of incubation, cell number, and the concentration of [3H]tyrosine in the medium. From velocity vs. [3H]tyrosine concentration experiments, two apparent K(m) values were obtained: K(m1) = 10 ± 2 μM; K(m2) = 140 ± 10 μM. Substrate inhibition occurred with tyrosine concentrations between 20 and 50 μM. The reaction was twice as fast at pH 5.5 as at pH 7.4. α,α' Dipyridyl (1 mM) caused major inhibition (75%) when [3H]tyrosine concentration was 10 μM. L 3 Iodotyrosine was a competitive inhibitor with K(i) = 0.3 μM. Dopamine was a noncompetitive inhibitor with K(i) = 500 μM. 1 Norepinephrine had no effect. These results show that the hydroxylation of tyrosine by living N1E 115 cells has many of the properties of the reaction catalyzed by purified tyrosine 3 monooxygenase from normal tissue.

AB - Tyrosine hydroxylation was studied in intact cells of mouse neuroblastoma clone N1E 115 which have high levels of tyrosine 3 monooxygenase and which have been fully characterized for tyrosine transport. Measurement of [3H]OH formed from L [3,5 3H]tyrosine in the medium was the method of assay and [3H]OH formed was stoichiometric with the formation of L [3H]3,4 dihydroxyphenylalanine. Tyrosine hydroxylation was dependent on time of incubation, cell number, and the concentration of [3H]tyrosine in the medium. From velocity vs. [3H]tyrosine concentration experiments, two apparent K(m) values were obtained: K(m1) = 10 ± 2 μM; K(m2) = 140 ± 10 μM. Substrate inhibition occurred with tyrosine concentrations between 20 and 50 μM. The reaction was twice as fast at pH 5.5 as at pH 7.4. α,α' Dipyridyl (1 mM) caused major inhibition (75%) when [3H]tyrosine concentration was 10 μM. L 3 Iodotyrosine was a competitive inhibitor with K(i) = 0.3 μM. Dopamine was a noncompetitive inhibitor with K(i) = 500 μM. 1 Norepinephrine had no effect. These results show that the hydroxylation of tyrosine by living N1E 115 cells has many of the properties of the reaction catalyzed by purified tyrosine 3 monooxygenase from normal tissue.

UR - http://www.scopus.com/inward/record.url?scp=0017178593&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0017178593&partnerID=8YFLogxK

M3 - Article

C2 - 12170597

AN - SCOPUS:0017178593

VL - 27

SP - 1113

EP - 1118

JO - Journal of Neurochemistry

JF - Journal of Neurochemistry

SN - 0022-3042

IS - 5

ER -