Design and Conformation of Peptides Containing .ALPHA.,.ALPHA.-Disubstituted .ALPHA.-Amino Acids.

Conformation of side groups in amino acids and peptides.

Action of carboxypeptidase toward peptides containing unnatural aromatic amino acids.

Science, a weekly journal founded in 1880, is published each Friday by the American Association for the Advancement of Science at the Business Press, 10 McGovern Ave., Lancaster, Pa. Editorial and Advertising Offices, 1515 Massachusetts Ave., N.W., Washington 5, D. C. Telephone, Executive 6060. Cable address, SCIMAG, Washington, D. C. Entered as second-class matter at the Post Office at Lancast...

Solid phase synthesis of peptides containing backbone-fluorinated amino acids.

Backbone-fluorinated amino acids exhibit unique conformational behaviour, and have potential utility as components of bioactive shape-controlled peptides. However, methods for the elaboration of backbone-fluorinated amino acids have thus far been limited to solution phase peptide coupling reactions. In this paper, protocols are developed that allow the successful manipulation of backbone-fluori...

Amino Acids, Amines and Peptides of Ram

Epididymal semen was obtained from rams with a fistula present in the vas deferens (Tadmor & Schindler, 1966). It was deproteinized immediately, and the protein-free clear supernatant evaporated to dryness in vacuo at a temperature not exceeding 55\s=deg\C. The residue was taken up with about 10 ml water, and the solution thus obtained used for determination of both amines and amino acids. For ...

Nucleophilicities of amino acids and peptides.

The kinetics of the reactions of amino acids with stabilized diarylcarbenium ions (Ar(2)CH(+)) have been studied photometrically in aqueous solution at variable pH. In the range of 10.5 < pH < 12, the amino acids react much faster than the competing nucleophiles hydroxide and water. Though the pK(aH) values of the amino acids vary by almost four units, the nucleophilic reactivities of all prima...