Biomaterial Database

General and specific porins from bacterial outer membranes. 1998

T Schirmer

Department of Structural Biology, Biozentrum, University of Basel, Switzerland.

Over the past years, the three-dimensional structures of several bacterial porins have been determined to high resolution. Apart from revealing an unusual type of architecture, the hollow beta-barrel, they have made it possible to investigate in detail various structure-function relationships. Characteristics of ion flow through (native and modified) porins inserted into artificial bilayers have been related to the electrostatic properties of the pores. The structural basis of voltage induced pore closing, however, is still not resolved. The remarkable ability of maltoporin to allow translocation of long maltodextrin molecules through the small channel has been traced back to the presence of an elongated hydrophobic patch at the channel lining.

UI	MeSH Term	Description	Entries
D008051	Lipid Bilayers	Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.	Bilayers, Lipid,Bilayer, Lipid,Lipid Bilayer
D008854	Microscopy, Electron	Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.	Electron Microscopy
D008958	Models, Molecular	Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.	Molecular Models,Model, Molecular,Molecular Model
D011134	Polysaccharides	Long chain polymeric CARBOHYDRATES composed of MONOSACCHARIDES linked by glycosidic bonds.	Glycan,Glycans,Polysaccharide
D011487	Protein Conformation	The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).	Conformation, Protein,Conformations, Protein,Protein Conformations
D011991	Receptors, Virus	Specific molecular components of the cell capable of recognizing and interacting with a virus, and which, after binding it, are capable of generating some signal that initiates the chain of events leading to the biological response.	Viral Entry Receptor,Viral Entry Receptors,Virus Attachment Factor,Virus Attachment Factors,Virus Attachment Receptor,Virus Attachment Receptors,Virus Entry Receptor,Virus Entry Receptors,Virus Receptor,Virus Receptors,Attachment Factor, Virus,Attachment Factors, Virus,Attachment Receptor, Virus,Attachment Receptors, Virus,Entry Receptor, Viral,Entry Receptor, Virus,Entry Receptors, Viral,Entry Receptors, Virus,Receptor, Viral Entry,Receptor, Virus,Receptor, Virus Attachment,Receptor, Virus Entry,Receptors, Viral Entry,Receptors, Virus Attachment,Receptors, Virus Entry
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
D013329	Structure-Activity Relationship	The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.	Relationship, Structure-Activity,Relationships, Structure-Activity,Structure Activity Relationship,Structure-Activity Relationships
D015640	Ion Channel Gating	The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability.	Gating, Ion Channel,Gatings, Ion Channel,Ion Channel Gatings
D018272	Porins	Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.	Pore Protein,Pore Proteins,Porin,Protein, Pore,Proteins, Pore