An activity similar to that of dipeptidyl aminopeptidase I (DAP I) which releases dipeptide from Gly-Argp-nitroanilide (Gly-Arg-pNA) was detected in a Pseudomonas sp. An enzyme was isolated and purified about 400-fold by a series of column chromatographies. The enzyme, named DAP BI (DAP from bacteria, type I), was revealed to be homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and isoelectric focusing. The molecular mass was estimated to be 82 kDa by SDS-PAGE and 65 kDa by gel filtration, suggesting that the enzyme may be a monomer. The enzyme had an isoelectric point of 4.7. It is optimally active at pH 9.0. The K m and V max of the enzyme for Gly-Arg-pNA were 0.25 mM and 195 mol/min/mg, respectively. The purified enzyme did not hydrolyze Gly-Phe-pNA, which was also a substrate for DAP I, whereas it hydrolyzed Arg-Arg-4-methoxy-␤-naphthylamide (Arg-Arg-MNA), a model substrate for DAP III. The K m and V max for Arg-Arg-MNA were 0.019 mM and 145 mol/min/mg, respectively. This purified enzyme can also catalyze the removal of Asp-Arg from the N termini of angiotensins I and II. The enzyme activity was completely inhibited by Zn(II) (0.5 mM), tosyl-L-Lys-chloromethyl ketone (0.1 mM), and leupeptin (0.1 mM) and partially inhibited by Co(II) (0.5 mM) and chymostatin (0.1 mM), whereas the enzyme was not affected by general serine protease inhibitors (phenylmethylsulfonyl fluoride and diisopropylfluorophosphate) and thiol protease inhibitors. The substrate specificity, classification of catalytic site, and other enzymatic properties demonstrate that this enzyme is distinct from the previously described mammalian DAPs I and III and Saccharomyces cerevisiae DAP III. These results indicate that DAP BI may be a new type of the DAP family.Dipeptidyl aminopeptidase (DAP) is capable of sequentially removing dipeptides from the amino termini of peptides and proteins. In mammalian cells, four distinct enzymes with DAP activity have been purified from the liver, brain, and pituitary on the basis of substrate specificity by using unique naphthylamide (NA) substrates, specific pH optima, and catalytic classification (13, 15). DAP I (cathepsin C) cleaves Gly-Arg-␤-naphthylamide (Gly-Arg-␤NA) and Gly-Phe-␤NA at pH 6, and DAP II cleaves Lys-Ala-␤NA with a pH optimum of 5. DAP III degrades Arg-Arg-␤NA with a pH optimum of 8 to 9, while DAP IV hydrolyzes Gly-Pro-␤NA at pH 8. DAP I is a lysosomal cysteine protease belonging to the papain superfamily. It possesses a broad specificity (20) for liberating dipeptides whose amino-terminal amino acid is not basic (Arg or Lys) and whose penultimate amino acid is not proline and that are not linked to proline through a peptide bond. DAP I appears to play an important role not only in intracellular protein degradation, but also in cell growth and processing and activation of several enzymes (18). On the other hand, DAP III shows relatively narrow substrate specificity on dipeptide NAs but a wide range of activity on peptide substrates. In particular, DAP III pre...

Abstract. We report disseminated cysticercosis concurrent with taeniasis in a 31-year-old male Japanese, who had visited India three times and stayed for 1 month each time during the previous 1 year. The patient presented increasing numbers of subcutaneous nodules and expelled proglottids, although numerous cysts were also found in the brain in imaging findings, though no neurological symptoms were observed. Histopathological and serological findings strongly indicated cysticercosis. We found taeniid eggs in his stool by microscopic examination and revealed them as the Indian haplotype of Taenia solium by mitochondrial DNA analysis. We concluded that disseminated cysticercosis was caused by the secondary autoinfection with eggs released from the tapeworm carrier himself. After confirming the absence of adult worms in the intestine by copro-polymerase chain reaction, the patient was successfully treated with albendazole at a dose of 15 mg/kg/day for 28 days. Subcutaneous and intracranial lesions had completely disappeared by the end of the treatment period.

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A 20-year-old woman was hospitalized repeatedly because of intermittent bouts of intestinal obstruction and the symptoms usually improved with conservative treatments. One year after the first admission the patient was hospitalized in emergency and a laparotomy revealed a circular stricture with a pinhole perforation in the ileum. Histological sections of the stricture showed the characteristic features of microscopic polyangiitis varying from active to resolving stages, which were localized in the ileum. Fibrinoid necrosis, fibroblastic and fibrous proliferation of the intima and fibrous replacement of the media with a variable pan- and perivascular inflammatory cell infiltrate were characteristic in the muscular arteries and arterioles. Vascular occlusion by pale eosinophilic, fibrillar-like materials resembling livedo racemosa of the skin, was noticed in the small arterioles and capillaries. Under no prophylaxis, the postoperative course was uneventful with no recurrence of the illness at an 18-month follow up. The pathological alterations were distributed focally, occasionally segmentally, and haphazardly, and required detailed examination by stepwise sections for the histological diagnosis.

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