J. Mandelstam

Bio: J. Mandelstam is an academic researcher from National Institute for Medical Research. The author has contributed to research in topics: Enzyme & Escherichia coli. The author has an hindex of 7, co-authored 7 publications receiving 309 citations.

Turnover of protein in starved bacteria and its relationship to the induced synthesis of enzyme.

Abstract: Turnover of Protein in Starved Bacteria and its Relationship to the Induced Synthesis of Enzyme

Isolation of Lysozyme-soluble Mucopeptides from the Cells Wall of Escherichia coli

Abstract: THE cell walls of the Gram-positive bacteria have been shown by Salton1 and by Cummins and Harris2 to consist mainly of polymers, later termed mucopeptides, containing a limited number of amino-acids (usually four), two amino-sugars and sometimes one or more hexoses. Two of the amino-acids, alanine and glutamic acid, are, at least partly, in the D-form. This, together with the occurrence of muramic acid, and sometimes of diaminopimelic acid as well, distinguishes mucopeptides from other types of macro-molecule. A further characteristic is sensitivity to lysozyme. The mucopeptides from some bacterial species are completely digested by this enzyme, and all appear to be attacked slightly3. The synthesis of mucopeptide in washed suspensions is inhibited by penicillin4,5.

Amino Acid Metabolism in Mammalian Cell Cultures

Abstract: The present article \"is a progress report rather than a review and in large part summarizes studies from a single laboratory\" on the minimal essential medium for cultivation of mammalian cells in either monolayer or suspension. Every cell culture examined, whether human or animal in origin, required at least 13 amino acids for survival and growth. All the cultured human cells examined were found to contain large amounts of glutathione, taurine, glutamine, ammonia, and glutamic acid. [The SCI® indicates that this paper was cited 2,255 times in the period 1961-1975.]

Cyclic Adenosine Monophosphate in Bacteria

Abstract: Both cyclic AMP and a specific inducer acting in concert are required for the synthesis of many inducible enzymes in E. coli. Little enzyme is made in the absence of either. In contrast to the specific inducers which stimulate the synthesis only of the proteins required for their metabolism, cyclic AMP controls the synthesis of many proteins. Glucose and certain other carbohydrates decrease the differential rate of synthesis of inducible enzymes by lowering cyclic AMP concentrations. In the lac operon, cyclic AMP acts at the promoter site to facilitate initiation of transcription. This action requires another protein, the cyclic AMP receptor protein. The nucleotide stimulates tryptophanase synthesis at a translational level. The action of cyclic AMP in E. coli may serve as a model to understand its action on transcriptional and translational processes in eukaryotes.

Beta-lactam Antibiotics: From Antibiosis to Resistance and Bacteriology

Abstract: This review focuses on the era of antibiosis that led to a better understanding of bacterial morphology, in particular the cell wall component peptidoglycan. This is an effort to take readers on a tour de force from the concept of antibiosis, to the serendipity of antibiotics, evolution of beta-lactam development, and the molecular biology of antibiotic resistance. These areas of research have culminated in a deeper understanding of microbiology, particularly in the area of bacterial cell wall synthesis and recycling. In spite of this knowledge, which has enabled design of new even more effective therapeutics to combat bacterial infection and has provided new research tools, antibiotic resistance remains a worldwide health care problem.