Biomaterial Database

Conformational changes in the extracellular beta-lactamase I from Bacillus cereus 569/H/9. 1974

R B Davies, and E P Abraham

1. The thermal denaturation and precipitation of beta-lactamase I from Bacillus cereus 569/H/9 at 60 degrees C are reversible, a soluble and almost fully active enzyme being obtained after solution of the precipitate in 5m-guanidinium chloride or 8m-urea and subsequent removal of the denaturing agent. 2. Inactivation of beta-lactamase I occurs rapidly between 50 degrees and 55 degrees C and is shown by circular-dichroism spectra to be accompanied by an extensive conformational change. 3. A change to a different conformation occurs in 6m-urea. This change is also reversible; refolding with almost complete recovery of enzymic activity occurs within 5min of dilution of the denaturing agent. 4. Inactivation of beta-lactamase I at pH3.0 and 11.0 is also associated with conformational changes, since a proportion of the lost activity is recovered within 5min of adjustment of the pH to 7.0.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D010400	Penicillin G	A penicillin derivative commonly used in the form of its sodium or potassium salts in the treatment of a variety of infections. It is effective against most gram-positive bacteria and against gram-negative cocci. It has also been used as an experimental convulsant because of its actions on GAMMA-AMINOBUTYRIC ACID mediated synaptic transmission.	Benzylpenicillin,Benpen,Benzylpenicillin Potassium,Coliriocilina,Crystapen,Or-pen,Parcillin,Pekamin,Pengesod,Penibiot,Penicilina G Llorente,Penicillin G Jenapharm,Penicillin G Potassium,Penicillin G Sodium,Penicillin Grünenthal,Penilevel,Peniroger,Pfizerpen,Sodiopen,Sodipen,Sodium Benzylpenicillin,Sodium Penicillin,Unicilina,Ursopen,Van-Pen-G
D010405	Penicillinase	A beta-lactamase preferentially cleaving penicillins. (Dorland, 28th ed) EC 3.5.2.-.	beta-Lactamase I,AER-I beta-Lactamase,Benzylpenicillinase,Carbenicillinase,Exopenicillinase,beta Lactamase III,beta Lactamase RP4,gamma-Penicillinase,AER I beta Lactamase,Lactamase RP4, beta,beta Lactamase I,beta-Lactamase, AER-I,gamma Penicillinase
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
D011489	Protein Denaturation	Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.	Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D003956	Dialysis	A process of selective diffusion through a membrane. It is usually used to separate low-molecular-weight solutes which diffuse through the membrane from the colloidal and high-molecular-weight solutes which do not. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Dialyses
D006146	Guanidines	A family of iminourea derivatives. The parent compound has been isolated from mushrooms, corn germ, rice hulls, mussels, earthworms, and turnip juice. Derivatives may have antiviral and antifungal properties.
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.