Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport.

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Abstract Text:

Frank Orlik,Christian Andersen,Roland Benz,

The three-dimensional structure of the malto-oligosaccharide-specific LamB-channel of Escherichia coli (also called maltoporin) is known from x-ray crystallography. The central constriction of the channel formed by the external loop 3 is controlled by a tyrosine residue (Y118). Y118 was replaced by site-directed mutagenesis by ten other amino acids (alanine, isoleucine, asparagine, serine, cysteine, aspartic acid, arginine, histidine, phenylalanine, and tryptophane) including neutral ones, negatively and positively charged amino acids to study the effect of their size, hydrophobicity, and charge on ion transport through LamB. The mutant proteins were purified to homogeneity. They were reconstituted into lipid bilayer membranes and single-channel conductance and ion selectivity were measured to get insight into the mechanism of ion transport through LamB. The mutation of Y118 to any other nonaromatic amino acid led to a substantial increase of the single-channel conductance by more than a factor of six at maximum. The highest effect was observed for Y118D. Additionally, a nonlinear relationship between the salt concentration in the aqueous phase and the channel conductance was observed for this mutant, indicating strong discrete charge effects on ion conductance. For all other mutants, with the exception of Y118R, linear relationships were found between single-channel conductance and bulk aqueous concentration. The individual hydrophobicity indices of the amino acids introduced inside the central constriction of the LamB channel had a somewhat smaller effect on the single-channel conductance as compared with the effect of their size and charge.

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Publishing Authors By Initials

F Orlik,C Andersen,R Benz,

For similar amino acids, peptides, and proteins: amino acids: amino acids, cyclic: amino acids, aromatic: tyrosine research abstracts see: amino acids, peptides, and proteins: amino acids: amino acids, cyclic: amino acids, aromatic: tyrosine research

PUBMED ID PMID:

MEDLINE DATE:

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Journal Published:

PUBLICATION TYPE: Research Support, Non-U.S. Gov

Journal: Biophysical journal

VOLUME: 82

Page Numbers: 2466-75

Journal Abbreviation: Biophys. J.

ISSN: 0006-3495

DAY: 27

MONTH: May

YEAR: 2002

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 370626

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Keywords Mesh Terms:

KEYWORDS: Tyrosine

MESH TERMS: metabolism

Chemical & Substance for Abstract: Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport. Information

Substance Name: Tyrosine

Registry Number: 55520-40-6

Grant and Affiliation Information for Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport.

AFFILIATION: Lehrstuhl für Biotechnologie, Theodor-Boveri-Institut (Biozentrum) der Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany.

Country: United States

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: Biophys J

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB Maltoporin channel of Escherichia coli I Effect on ion transport Related Publications

• Aging impacts transcriptomes but not genomes of hormone-dependent breast cancers.
• Anti-oncomir suppression of tumor phenotypes.
• Breast cancer growth prevention by statins.
• Characterization of channel-forming activity in muscle biopsy from a porin-deficient human patient.
• Comparison of MC4PC and MDL-QSAR rodent carcinogenicity predictions and the enhancement of predictive performance by combining QSAR models.
• Coordinate suppression of ERBB2 and ERBB3 by enforced expression of micro-RNA miR-125a or miR-125b.
• Corynebacterium diphtheriae: identification and characterization of a channel-forming protein in the cell wall.
• Development of an Integrated Approach to Cancer Disparities: One Cancer Center's Experience.
• Enhanced NF kappa B and AP-1 transcriptional activity associated with antiestrogen resistant breast cancer.
• Evaluation of the rate constants of sugar transport through maltoporin (LamB) of Escherichia coli from the sugar-induced current noise.
• LamB (maltoporin) of Salmonella typhimurium: isolation, purification and comparison of sugar binding with LamB of Escherichia coli.
• MANIFESTATIONS OF THE ROSS RIVER AND BARMAH FOREST ARBOVIRUSES: A Clinical Challenge for Chiropractors.
• Noise analysis of ion current through the open and the sugar-induced closed state of the LamB channel of Escherichia coli outer membrane: evaluation of the sugar binding kinetics to the channel interior.
• Of alternate and designated IACUC members. Regulations trump convenience.
• PH-induced collapse of the extracellular loops closes Escherichia coli maltoporin and allows the study of asymmetric sugar binding.
• PNEUMONIA FROM A PUBLIC HEALTH VIEW POINT.
• Pneumonia Quarantine.
• Pore formation by the Bordetella adenylate cyclase toxin in lipid bilayer membranes: Role of voltage and pH.
• Proteasome-regulated ERBB2 and estrogen receptor pathways in breast cancer.
• Rate constants of sugar transport through two LamB mutants of Escherichia coli: comparison with wild-type maltoporin and LamB of Salmonella typhimurium.
• Regulated Fox-2 isoform expression mediates protein 4.1R splicing during erythroid differentiation.
• Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (Maltoporin) channel of Escherichia coli. I. Effect on ion transport.
• Site-directed mutagenesis of tyrosine 118 within the central constriction site of the LamB (maltoporin) channel of Escherichia coli. II. Effect on maltose and maltooligosaccharide binding kinetics.
• Site-directed mutagenesis within the central constriction site of ScrY (sucroseporin): effect on ion transport and comparison of maltooligosaccharide binding to LamB of Escherichia coli.
• The administration of enemas to infants and children.
• The deletion of 70 amino acids near the N-terminal end of the sucrose-specific porin ScrY causes its functional similarity to LamB in vivo and in vitro.
• [Not Available.]
• [Not Available.]
• [Not Available.]
• [Not Available.]