Ricin toxin contains at least three galactose-binding sites located in B chain subdomains 1 alpha, 1 beta, and 2 gamma

Biochemistry
A E FrankelM C Willingham

Abstract

Ricin toxin, the heterodimeric 65 kDa glycoprotein synthesized in castor bean seeds, consists of a cell binding lectin subunit (RTB) disulfide linked to an rRNA N-glycosidase protein synthesis inactivating subunit (RTA). While X-ray crystallography and equilibrium dialysis suggested two sugar-combining sites located in subdomains 1 alpha and 2 gamma, biochemical and mutational analyses suggested the existence of a third lectin site. We performed oligonucleotide-directed mutagenesis on RTB cDNA to create mutants with modifications in subdomains 1 alpha, 2 gamma, and either 1 beta or 2 alpha. The triple-site mutant RTBs were expressed in insect cells. Partially purified recombinant proteins obtained from infected cell extracts and cell supernatants were characterized for asialofetuin and cell binding, immunoreactivites, ability to reassociate with RTA, and recombinant heterodimer cell cytotoxicity. Yields of both triple-site mutants were similar to the parent double-site mutant. Both mutants showed immunoreactivity with a panel of anti-RTB monoclonal and polyclonal antibodies. The triple-site mutant with modification of amino acid residues in subdomains 1 alpha, 2 alpha, and 2 gamma bound asialofetuin and cells similarly to the p...Continue Reading

References

Sep 26, 1978·Biochimica Et Biophysica Acta·C ZentzR Bourrillon
May 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·C SwimmerB C Guild
Oct 1, 1992·FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology·Y C Lee
Jan 1, 1991·Proteins·E Rutenber, J D Robertus
Apr 10, 1991·European Journal of Biochemistry·A Rivera-SagredoM Martín-Lomas
Dec 5, 1981·Journal of Molecular Biology·S PooleW Rowekamp
Jun 1, 1995·Nature Structural Biology·K Drickamer
Oct 1, 1995·Seminars in Cancer Biology·A E FrankelM C Willingham
Jan 1, 1996·Bioconjugate Chemistry·A FrankelM Willingham

❮ Previous
Next ❯

Citations

Nov 30, 2011·European Biophysics Journal : EBJ·John W BradyAttilio Cesàro
Dec 24, 1997·Leukemia Research·R J Kreitman
Jun 6, 2000·Advanced Drug Delivery Reviews·I Pastan, R J Kreitman
Dec 1, 1996·International Journal of Immunopharmacology·T FuA E Frankel
Aug 24, 2010·Food and Chemical Toxicology : an International Journal Published for the British Industrial Biological Research Association·Payal SehgalR Vijayaraghavan
Nov 20, 2004·BioEssays : News and Reviews in Molecular, Cellular and Developmental Biology·Otto Schmidt, Ulrich Theopold
Jun 9, 2004·European Journal of Biochemistry·Alma G KourmanovaJurij V Kozlov
May 16, 1997·Carbohydrate Research·A E FrankelM C Willingham
Jul 5, 2005·Expert Opinion on Investigational Drugs·R J Kreitman
May 18, 1999·Biochemical and Biophysical Research Communications·M HelmyG Piéroni
Mar 31, 2015·Journal of Agricultural and Food Chemistry·David L Brandon, Lisa M Adams
Oct 20, 2017·Clinical and Vaccine Immunology : CVI·Madison Zuverink, Joseph T Barbieri
Jun 28, 2001·FASEB Journal : Official Publication of the Federation of American Societies for Experimental Biology·W J PeumansE J Van Damme

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.