Epidermal Keratinization: Localization of Isotopically Labeled Amino Acids*

Epidermal keratinization: localization of isotopically labeled amino acids.

Synthesis of isotopically labeled saturated fatty acids.

An approach to the synthesis of isotopically labeled saturated fatty acids is outlined which is based on the copper-catalyzed coupling of an omega-bromo acid with an isotopically labeled Grignard reagent. The method provides high yields of pure products and offers considerable flexibility in the type of isotopically enriched compound that can be prepared.-DasGupta, S. K., D. M. Rice, and R. G. ...

Differentially localized incorporation of amino acids in relation to epidermal keratinization in the newborn rat.

Incorporation of tritiated methionine, phenylalanine, leucine, glycine and histidine into protein in the epidermis of the newborn rat was studied by autoradiography. Methionine, phenylalanine and leucine behaved similarly. Thirty minutes after injection, radioactivity was detected in both nucleus and cytoplasm of the basal, spinous and granular cells with a greater intensity over the cells of t...

Peptide mass fingerprinting using isotopically encoded photo-crosslinking amino acids.

When isotopically labelled photo-crosslinking amino acids are site-specifically incorporated into proteins, in combination with the corresponding non-labeled analogue, cross-linked tryptic peptides are easily identified in mass spectra via characteristic "doublet" patterns.

Chemoenzymatic Assembly of Isotopically Labeled Folates.

Pterin-containing natural products have diverse functions in life, but an efficient and easy scheme for their in vitro synthesis is not available. Here we report a chemoenzymatic 14-step, one-pot synthesis that can be used to generate 13C- and 15N-labeled dihydrofolates (H2F) from glucose, guanine, and p-aminobenzoyl-l-glutamic acid. This synthesis stands out from previous approaches to produce...