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S Levit

Publications and source records attributed to S Levit.

23 records · Page 2Linked to original sources
PubMed1970

On the active site of elastase: Partial mapping by means of specific peptide substrates.

RNase-S peptide as well as some related octa- and hexapeptides were found to be highly, reactive substrates of porcine elastase (e.g. Ala(4)-Lys-Phe: K(m) = 4500 M(-1), k(cat) = 32 sec(-1), C = 1.4 x 10(5) M(-1) sec(-1)). Comparison of the various peptides led to the conclusion that the active site of porcine elastase is composed of 6-7 subsites (c.f. [1]). Preliminary mapping shows that subsites S(2), S'(1) and S'(2) have hydrophobic character. Occupation of subsite S(4) by the substrate is important for efficient hydrolysis. Binding at this subsite was found to be stereospecific.

Journal Article↗
PubMedDate not supplied

Adherence of Staphylococcus aureus to squamous epithelium: role of fibronectin and teichoic acid.

For bacteria to colonize mucosal surfaces, they must be able to attach to epithelial cells. One of the most important factors in determining this attachment is bacterial adherence. The preferential adherence of a bacteria to a particular tissue influences the site of infection and the virulence of the organism. The glycoprotein fibronectin mediates adhesion of the bacteria to eukaryotic cells. Recent investigations have revealed that the precise locations of the binding sites for Staphylococcus aureus are close to the NH2-terminal and at the COOH-terminal regions of the fibronectin molecule. Teichoic acids are major cell-wall components of staphylococci that have been found to mediate the capacity of the bacteria to adhere to epithelial cells. By use of biologic assays based on the specific adherence of S. aureus to nasal epithelium, it was determined that the binding site for fibronectin appears to be teichoic acid.

Animals↗