PBP 2 a Penicillin Binding Protein ANA BERNAL

PBP 2 a Penicillin Binding Protein ANA BERNAL BRITTANY SOTO BIOQUEST CONSORTIUM AT UTK 17 AUGUST 2012

Cell Wall �Cell wall is formed by Peptidoglycan �Peptidogylcan consists of repeating polymer sugars and amino acids. �Growing peptide chains are cross linked by transpeptidase to form a bilayer. http: //www. nature. com/nrmicro/journal/v 6/n 1/box/nrmicro 1795_BX 3. html

β-Lactam Antibiotics �Large classification of antibiotics Penicillin Methicillin �Most commonly used antibiotics in the past decade. http: //pubs. acs. org/cen/coverstory/83/8325 penicillin. h tml

PBP Proteins �β- lactam antibiotics bind to the cell wall by PBP proteins �Prevents transpeptidase from cross linking �The cell wall is weakened and osmotic pressure forces cell lyses http: //www. pnas. org/content/98/19/10886. full

PBP 2 a Proteins �Mec. A gene produces PBP 2 a. �PBP 2 a is 78 k. Da and has a low affinity to β-lactam antibiotics �PBP 2 a is responsible for the growing resistance in Staphylococcus aureus.

Staphlyococcus aureus � Gram-positive bacteria, naturally found in the skin and mucous membranes of mammals. � MRSA: Methicillin resistant strain of S. aureus Leading acquired hospitalized infections In the last 5 years, MRSA has surpassed the number of deaths attributed to AIDS. http: //www. health-reply. com/staphylococcus-aureuscommunity-acquired-pneumonia/

S. aureus Resistance to PBP 2 a �PBP 2 a have low affinity for β- lactam antibiotics �Allows transpeptidase to cross link D-alanine with another peptide chain in the presence of equal concentrations of βlactam antibiotics that would inhibit PBP proteins http: //www. pnas. org/content/98/19/10886. full

Future Research �Modifications to β-lactam antibiotics �Characterization of PBP 2 a proteins focusing on kinetic parameters �Developing a new classification of antibiotics that target siderophores, low molecular weight, high affinity iron chelating agents.