Biomaterial Database

Iron-repressible outer membrane proteins of Helicobacter pylori involved in heme uptake. 1995

D J Worst, and B R Otto, and J de Graaff

Department of Medical Microbiology, Faculty of Medicine, Vrije Universiteit, Amsterdam, The Netherlands.

Helicobacter pylori is known to be a causative agent of gastritis and peptic ulcer disease in humans. The acquisition of iron from the human host may contribute greatly to the virulence of this organism. To study this, H. pylori was cultured under iron-restrictive conditions to induce synthesis of possible iron-regulated outer membrane proteins. This was achieved by the addition of 20% (vol/vol) heat-inactivated newborn calf serum, which contains iron-binding proteins like transferrin and albumin, and no free iron. The newborn calf serum was able to bind free ionic iron in brucella broth culture medium. Electrophoretic analysis of outer membrane preparations from H. pylori cultured under conditions of iron restriction showed several proteins to be present at elevated levels. These appeared to be iron-repressible outer membrane proteins (IROMPs). In addition, IROMPs with molecular sizes of 77, 50, and 48 kDa were isolated by use of hemin-agarose affinity chromatography. These three heme-binding IROMPs might be involved in the uptake of heme from the host and might therefore be important virulence factors of H. pylori.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D003470	Culture Media	Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.	Media, Culture
D006418	Heme	The color-furnishing portion of hemoglobin. It is found free in tissues and as the prosthetic group in many hemeproteins.	Ferroprotoporphyrin,Protoheme,Haem,Heme b,Protoheme IX
D006736	Horses	Large, hoofed mammals of the family EQUIDAE. Horses are active day and night with most of the day spent seeking and consuming food. Feeding peaks occur in the early morning and late afternoon, and there are several daily periods of rest.	Equus caballus,Equus przewalskii,Horse, Domestic,Domestic Horse,Domestic Horses,Horse,Horses, Domestic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001425	Bacterial Outer Membrane Proteins	Proteins isolated from the outer membrane of Gram-negative bacteria.	OMP Proteins,Outer Membrane Proteins, Bacterial,Outer Membrane Lipoproteins, Bacterial
D001426	Bacterial Proteins	Proteins found in any species of bacterium.	Bacterial Gene Products,Bacterial Gene Proteins,Gene Products, Bacterial,Bacterial Gene Product,Bacterial Gene Protein,Bacterial Protein,Gene Product, Bacterial,Gene Protein, Bacterial,Gene Proteins, Bacterial,Protein, Bacterial,Proteins, Bacterial
D016480	Helicobacter pylori	A spiral bacterium active as a human gastric pathogen. It is a gram-negative, urease-positive, curved or slightly spiral organism initially isolated in 1982 from patients with lesions of gastritis or peptic ulcers in Western Australia. Helicobacter pylori was originally classified in the genus CAMPYLOBACTER, but RNA sequencing, cellular fatty acid profiles, growth patterns, and other taxonomic characteristics indicate that the micro-organism should be included in the genus HELICOBACTER. It has been officially transferred to Helicobacter gen. nov. (see Int J Syst Bacteriol 1989 Oct;39(4):297-405).	Campylobacter pylori,Campylobacter pylori subsp. pylori,Campylobacter pyloridis,Helicobacter nemestrinae
D033862	Iron-Binding Proteins	Proteins that specifically bind to IRON.	Iron-Binding Protein,Iron Binding Protein,Iron Binding Proteins,Protein, Iron-Binding
D033902	Periplasmic Binding Proteins	Periplasmic proteins that scavenge or sense diverse nutrients. In the bacterial environment they usually couple to transporters or chemotaxis receptors on the inner bacterial membrane.	Periplasmic Binding Protein,Binding Protein, Periplasmic,Binding Proteins, Periplasmic,Protein, Periplasmic Binding