Fragment of an endogenous inhibitor produced in Escherichia coli for calcium-activated neutral protease (CANP) retains an inhibitory activity

AbstractA C-terminal fragment of an endogenous rabbit liver inhibitor for calcium-activated neutral protease (CANP) was produced in Escherichia coli and its inhibitory activity was examined after purification. The truncated inhibitor (373 amino acid residues), which contains two internal repeat structures, inhibits 2 mol CANP whereas the native liver inhibitor (639 residues), containing four internal repeat structures, inhibits 4 mol CANP. This supports the hypothesis that the repeating unit is the functional unit of inhibition. The results also indicate that post-translational modification of the inhibitor is not essential for inhibition

Molecular cloning and sequencing of cDNA for rat cathepsin H Homology in pro-peptide regions of cysteine proteinases

AbstractA cDNA for rat cathepsin H was isolated and sequenced. The deduced protein comprising 333 amino acid residues is composed of a typical signal sequence (21 residues), a pro-peptide region (92 residues) and a mature enzyme region (220 residues). The amino acid sequence in the pro-peptide region, in particular, residues Phe-(−41) to Ser-(−29) of cathepsin H, is highly homologous to the pro-peptide regions of other cysteine proteinases. This homologous region may play a role in the processing of cysteine proteinases

Parity-broken ground state for the spin-1 pyrochlore antiferromagnet

The ground-state properties of the spin-1 pyrochlore antiferromagnet are studied by applying the VBS-like tetrahedron-unit decomposition to the original spin system. The symmetrization required on every vertex is taken into account by introducing a ferromagnetic coupling. The pairwise effective Hamiltonian between the adjacent tetrahedrons is obtained by considering the next nearest neighbor and the third neighbor exchange interactions. We find that the transverse component of the spin chirality exhibits a long-range order, breaking the parity symmetry of the tetrahedral group, while the chirality itself is not broken.Comment: 4 pages, 3 figures, REVTeX(ver.3.1