beta-lactamase

Examples of beta-lactamase in the following topics:

• Antibiotics from Prokaryotes

  • Clavulanic acid (from S. clavuligerus) is a drug used in combination with some antibiotics (like amoxicillin) to block and/or weaken some bacterial-resistance mechanisms by irreversible beta-lactamase inhibition.

• Shuttle Vectors and Expression Vectors

  • The E. coli component of a yeast shuttle vector includes an origin of replication and a selectable marker, such as an antibiotic resistance like beta lactamase.

• Inhibiting Cell Wall Synthesis

  • β-Lactam (beta-lactam) and glycopeptide antibiotics work by inhibiting or interfering with cell wall synthesis of the target bacteria.
  • The first class of antimicrobial drugs that interfere with cell wall synthesis are the β-Lactam antibiotics (beta-lactam antibiotics), consisting of all antibiotic agents that contains a β-lactam nucleus in their molecular structures.
  • Bacteria often develop resistance to β-lactam antibiotics by synthesizing a β-lactamase, an enzyme that attacks the β-lactam ring.
  • To overcome this resistance, β-lactam antibiotics are often given with β-lactamase inhibitors such as clavulanic acid.
  • Describe the two types of antimicrobial drugs that inhibit cell wall synthesis: beta-lactam and glycopeptide antibiotics

• Beta-Lactam Antibiotics: Penicillins and Cephalosporins

  • A β-lactam (beta-lactam) ring, is a four-membered lactam .
  • They do this by expressing the β-lactamase gene.

• T Cell Receptors

  • The antigen receptor of MHC-restricted CD4 helper T cells and CD8 cytolytic T cell is a heterodimer consisting of two transmembrane polypeptide chains, designated alpha and beta, covalently linked to each other by disulfide bonds.
  • Each alpha and beta chain consists of one variable domain (V), one constant domain (C), a hydrophobic transmembrane region, and a short cytoplasmic region .
  • The recognition of peptide-MHC complexes is mediated by CDRs formed by both the alpha and beta chains of the TCR.
  • T cell receptor consists of alpha and beta chains, a transmembrane domain, and a cytoplasmic region.

• The Incorporation of Nonstandard Amino Acids

  • It is important to compare the structures of alanine and beta alanine.
  • In alanine, the side-chain is a methyl group; in beta alanine, the side-chain contains a methylene group connected to an amino group, and the alpha carbon lacks an amino group.
  • A rare exception to the dominance of α-amino acids in biology is the β-amino acid beta alanine (3-aminopropanoic acid), which is used in plants and microorganisms in the synthesis of pantothenic acid (vitamin B5), a component of coenzyme A.

• Bacterial Skin Diseases

  • Most cases of erysipelas are due to Streptococcus pyogenes (also known as beta-hemolytic group A streptococci), although non-group A streptococci can also be the causative agent.
  • Beta-hemolytic, non-group A streptococci include Streptococcus agalactiae, also known as group B strep or GBS.

• Naturally Occurring Antimicrobial Drugs: Antibiotics

  • There are mainly two classes of antimicrobial drugs: those obtained from natural sources (i.e. beta-lactam) antibiotic (such as penicillins, cephalosporins) or protein synthesis inhibitors (such as aminoglycosides, macrolides, tetracyclines, chloramphenicol, polypeptides); and synthetic agents.
  • A β-lactam (beta-lactam) ring is a four-membered lactam.
  • Rifamycin inhibits prokaryotic DNA transcription into mRNA by inhibiting DNA-dependent RNA polymerase by binding its beta-subunit.

• Recombinant DNA Technology

  • Most modern vectors contain a variety of convenient cleavage sites that are unique within the vector molecule (so that the vector can only be cleaved at a single site) and is located within a gene (frequently beta-galactosidase) whose inactivation can be used to distinguish recombinant from non-recombinant organisms at a later step in the process.
  • In these vectors, foreign DNA is inserted into a sequence that encodes an essential part of beta-galactosidase, an enzyme whose activity results in formation of a blue-colored colony on the culture medium that is used for this work.
  • Insertion of the foreign DNA into the beta-galactosidase coding sequence disables the function of the enzyme, so that colonies containing recombinant plasmids remain colorless (white).

• Antibiotic Classifications

  • Examples include the Beta-lactam antibiotics (penicillin derivatives (penams) ), cephalosporins (cephems), monobactams, and carbapenems) and vancomycin.