Thioredoxin from Escherichia coli

Journal Article · Wed Jan 25 04:00:00 EST 1978 · J. Biol. Chem.; (United States)

OSTI ID:7091065

Holmgren, A; Ohlsson, I; Grankvist, M L

A competition radioimmunoassay for Escherichia coli thioredoxin using /sup 125/I-labeled thioredoxin-S/sub 2/ and a double antibody technique was developed. The method permits determination of picomole amounts of thioredoxin in crude cell extracts and was used to study the localization of thioredoxin cell fractions. E. coli B was calculated to have approximately 10,000 copies of thioredoxin per cell mainly located in the soluble fraction after separation of the membrane and soluble fractions by gentle lysis and centrifugation. E. coli B tsnC mutants which are defective in the replication of phage T7 DNA in vivo and in vitro were examined for their content of thioredoxin. E. coli B tsnC 7004 contained no detectable level of thioredoxin in cell-free extracts examined under a variety of conditions. The results strongly suggest that tsnC 7004 is a nonsense or deletion mutant. Two other E. coli tsnC mutants, 7007 and 7008, contained detectable levels of thioredoxin in crude extracts as measured by thioredoxin reductase and gave similar immunoprecipitation reactions as the parent strain B/1. By radioimmunoassay incompletely cross-reacting material was present in both strains. These results show that tsnC 7007 and 7008 belong to a type of thioredoxin mutants with missence mutations in the thioredoxin gene affecting the function of thioredoxin as subunit in phage T7 DNA polymerase.

• Research Organization: Karolinska Institutet, Stockholm
• OSTI ID: 7091065
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 253:2; ISSN JBCHA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
62 RADIOLOGY AND NUCLEAR MEDICINE
ANTIBODIES
BACTERIA
BACTERIOPHAGES
BETA DECAY RADIOISOTOPES
BIOASSAY
COMPARATIVE EVALUATIONS
DAYS LIVING RADIOISOTOPES
DITHIOLS
DNA REPLICATION
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
ESCHERICHIA COLI
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LABELLED COMPOUNDS
MICROORGANISMS
MUTANTS
NUCLEI
NUCLEIC ACID REPLICATION
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PARASITES
POLYMERASES
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOISOTOPES
REAGENTS
THIOLS
TRACER TECHNIQUES
VIRUSES