Cephalosporin acylase (CA), a member of the N-terminal nucleophile hydrolase family, is activated through sequential primary and secondary autoproteolytic reactions with the release of a pro segment. We have determined crystal structures of four CA mutants. Two mutants are trapped after the primary cleavage, and the other two undergo secondary cleavage slowly. These structures provide a look at...

The crystal structure of the 2A proteinase from human rhinovirus serotype 2 (HRV2-2A(pro)) has been solved to 1.95 A resolution. The structure has an unusual, although chymotrypsin-related, fold comprising a unique four-stranded beta sheet as the N-terminal domain and a six-stranded beta barrel as the C-terminal domain. A tightly bound zinc ion, essential for the stability of HRV2-2A(pro), is t...

The NH?-terminal E-residue sequences of human and rabbit plasminogens were determined to be Glu-Pro-LeuAsp-Asp-Tyr-Val-Asn-X-Gln-Gly-Ala-. The cat plasminogen 12-residue sequence differed only in the 1st residue, in which aspartic acid replaced glutamic acid. The bovine plasminogen NH?-terminal 7-residue sequence was determined to be Asp -Leu -Leu -Asp -Asp -Tyr -Val-. The NH2terminal residue o...

To understand the structural and chemical basis for insect neuropeptide activity, we have designed, synthesized, and determined the conformation of a biologically active cyclic analog of the pyrokinins, an insect neuropeptide family that mediates myotropic (visceral muscle contractile) activity. Members of this insect neuropeptide family share the common C-terminal pentapeptide sequence Phe-Xaa...

A major cysteine proteinase (CPB) of Leishmania mexicana, that is predominantly expressed in the form of the parasite that causes disease in mammals, has been overexpressed in Escherichia coli and purified from inclusion bodies to apparent homogeneity. The CPB enzyme, CPB2.8, was expressed as an inactive pro-form lacking the characteristic C-terminal extension (CPB2.8DeltaCTE). Pro-region proce...

Abdnct-The stepwise synthesis of amino terminal pcntapcptide of alamethiin. Z-Aib-PrpAil+Ala-Aib-OMe, by the dicyclohexylcarbodiimide mediated couplings leads to extensive racemizatiun at the Ala and Pro residues. Racemization is hugely suppressed by the use of additives like N-hydroxysuccinimide and I-hydroxybcnzotriazole. The presence of diastereomeric peptides may be detected by the observat...