beta sheet

Examples of beta sheet in the following topics:

• RNA Bacteriophages

  • They adopt a secondary structure consisting of a six-stranded beta sheet and an alpha helix.

• Prions

  • All known prions induce the formation of an amyloid fold, in which the protein polymerises into an aggregate consisting of tightly-packed beta sheets.

• Antibody Proteins and Antigen Binding

  • All chains have a characteristic immunoglobulin fold in which two beta sheets create a "sandwich" shape, held together by interactions between conserved cysteines and other charged amino acids.

• Bovine Spongiform Encephalopathy

  • TSEs can arise in animals that carry an allele which causes previously normal protein molecules to contort by themselves from an alpha helix arrangement to a beta sheet, which is the disease-causing shape for the particular protein.

• Variant Creutzfeldt-Jakob Disease

  • Mutations in the gene for the prion protein can cause a misfolding of the dominantly alpha helical regions into beta pleated sheets.

• 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.

• 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.
  • 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 .

• 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.