Three Boc-protected fragments of the human leukocyte interferon, LeIFA, have been synthesized: I, BOC LeIFA (99-105) (BOC-Val-Ile-Gln-Gly-Val-Gly-Val); II, BOC LeIFA (116-119) (BOC-Ile-Leu-Ala-Val); III, BOC LeIFA (123-126) (BOC-Phe-GlnArg(Tos)-Ile). The presence of the Boc-group was desired so that these peptides could serve as intermediates in fragment condensation toward larger segments of i...

BACKGROUND Prostase/KLK4 is a member of the human kallikrein (KLK) gene family that is expressed in prostate epithelial cells under the regulation of androgenic hormones. In this study, we sought to characterize the substrate specificity of KLK4 in order to gain insight into potential physiological roles of the enzyme. METHODS A chimeric form of KLK4 was constructed in which the pro-region of...

Lipid A disaccharide synthase of Escherichia coli catalyzes the reaction 2,3-diacyl-GlcN-1-P + UDP-2,3-diacyl-GlcN----2',3'-diacyl-GlcN (beta,1'----6)2,3-diacyl-GlcN-1-P + UDP (Ray, B. L., Painter, G., and Raetz, C. R. H. (1984) J. Biol. Chem. 259, 4852-4859). Using a strain that overproduces the enzyme about 200-fold we have devised a simple purification to near homogeneity, utilizing two type...

Here we study the pattern of amino acid interchanges at spatially, locally conserved regions in globally dissimilar and unrelated proteins. By using a method which completely separates the amino acid sequence from its respective structure, this work addresses the question of which properties of the amino acids are the most crucial for the stability of conserved structural motifs. The proteins a...

Cholecystokinin (CCK)-like immunoreactivity (CCK-LI) in a pool of 12 dog brains was extracted sequentially into boiling water and cold 2% trifluoroacetic acid. Gel filtration on Sephadex G-50 revealed three main molecular forms detected by a carboxyl-terminal antibody; one was eluted in the position of CCK-58 (58 amino acid residues long); a second, in the position of CCK-8; and a third, near t...

(32)P-labelled phosphoglucomutase was digested with trypsin after denaturation and two peptides were isolated that contained the bulk of the radioactivity bound to peptides. Both peptides appeared to derive from an identical section of the molecule. Peptic and subtilisin digests of the tryptic peptides were prepared. The resulting radioactive peptides were purified and their sequences studied. ...

Protein S is a plasma factor essential for prevention of thrombosis, partly due to its activity as a cofactor for the plasma anticoagulant protease-activated protein C. To expand knowledge about structure-function relationships in homologous protein S molecules, studies of protein S from different species have been performed. Protein S anti-coagulant activity in human, monkey, bovine, and porci...