Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.1 (chymotrypsin)
 10,938 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Schistosomula of Schistosoma mansoni became resistant to antibody-dependent complement damage in vitro after pre-incubation with normal human erythrocytes (NHuE) whatever the ABO or Rh blood group. Resistant parasites were shown to acquire host decay accelerating factor (DAF), a 70 kDa glycoprotein attached to the membrane of NHuE by a GPI anchor. IgG2a mAb anti-human DAF (IA10) immunoprecipitated a 70 kDa molecule from 125I-labeled schistosomula pre-incubated with NHuE and inhibited their resistance to complement-dependent killing in vitro. Incubation of schistosomula with erythrocytes from patients with paroxysmal nocturnal hemoglobinuria (PNHE) or SRBC, which are DAF-deficient, did not protect the parasites from complement lesion. Supernatant of 100,000 x g collected from NHuE incubated for 24 h in defined medium was shown to contain a soluble form of DAF and to protect schistosomula from complement killing. Schistosomula treated with trypsin before incubation with NHuE ghosts did not become resistant to complement damage. On the other hand, pre-treatment with chymotrypsin did not interfere with the acquisition of resistance by the schistosomula. These results indicate that, in vitro, NHuE DAF can be transferred to schistosomula in a soluble form and that the binding of this molecule to the parasite surface is dependent upon trypsin-sensitive chymotrypsin-insensitive polypeptide(s) present on the surface of the worm.
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PMID:Mechanisms of evasion of Schistosoma mansoni schistosomula to the lethal activity of complement. 128 36

BOW is a 'new' low-frequency red-cell antigen, detected in 2 unrelated English blood donors, that is sensitive to alpha-chymotrypsin and pronase. Anti-BOW is present in many polyspecific reagents used to define low-frequency antigens. Red-cell groups of the proposita, R.B., and her family show that the BOW blood group segregates independently from the ABO, Rh, MNSs, P1 and Kell blood group systems.
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PMID:A new low-frequency antigen BOW (Bowyer). 321 70

Human-type blood group activities on the red blood cells (RBCs) of three chimpanzees were individually examined with commercial mouse monoclonal antibodies (anti-A, -B, -H, -M, -N, -Lea, and -Leb) as well as lectins (UEA-I and VGA) and conventional polyclonal antisera for the systems ABO, MN, Lewis, Rh-Hr, P, Kell, Kidd, Duffy, and Lutheran. For further analysis of the MN antigens, treatment of the RBCs with sialidase, trypsin, and chymotrypsin were employed. The activities recognized among the three chimpanzees were A, H, M, N, Leb, c, S, k, and Jka. The RBCs of the three individuals possessed the A antigen which showed the same serologic activity as the human A1. Those chimpanzee RBCs showed higher H-activity than the human A1 RBCs. The Lewis b activity was revealed by the absorption-elution method. The RBCs of the three individuals showed a reactivity to the polyclonal anti-M reagents, which was affected by both the sialidase and trypsin treatment. The RBCs of two individuals were agglutinated with the monoclonal anti-N. The receptor was sensitive to sialidase and chymotrypsin. The RBCs of the three individuals, however, did not react with the monoclonal anti-M or with one of the polyclonal anti-N. These results indicate structural differences in the glycophorins and MN antigens between the human and chimpanzee.
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PMID:Human-type blood group activities on chimpanzee erythrocytes with special reference to M and N. 323 60

The Baumgartner perfusion apparatus has been applied to the study of the interaction of platelets and tumor cells and their attachment to subendothelial structures. Cells derived from an anaplastic murine tumor (Hut 20 line) induced platelet aggregation and were included in platelet thrombi that deposited on vascular subendothelium in perfusion experiments with heparinized human blood. In contrast, perfusion of blood samples containing cells from a line derived from a human epithelial carcinoma of the lung (A549 line), which did not interact with platelets, resulted in the deposition of platelets alone, with no tumor cells or blood cells other than platelets being observed in the thrombus. Extremely large platelet-tumor cell thrombi were found at the vascular surface in Hut 20 perfusions using vessel segments which had been treated with alpha-chymotrypsin. These large heterogeneous thrombi perturbed blood flow through the system and entrapped both erythrocytes and white cells. In order to quantitate the deposition of tumor cells, Hut 20 cells were labeled with 125I-deoxyuridine and perfused in whole blood at a concentration of 3.7x10(5)/ml. Tumor cell incorporation into platelet-tumor cell thrombi on chymotrypsinized segments yielded about 30,000 cpm/mg of vascular tissue but this value was reduced some 2 orders of magnitude by the inclusion of PGE1 (1 ng/ml of perfusing blood; 2.8 microM) in parallel samples. Aspirin at 100 microM reduced tumor cell-dependent platelet aggregation but did not decrease the platelet-dependent deposition of radiolabeled Hut 20 cells on vascular subendothelium, suggesting the release reaction may not be of major significance in this interaction. Tumor cell-induced platelet aggregation was not observed in a perfusion experiment using blood from a patient with severe von Willebrand's disease. However addition of 0.1 vol of ABO-compatible, heterologous plasma as a source of factor VIII to the von Willebrand blood sample restored the platelet-dependent deposition of radiolabeled tumor cells to control values.
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PMID:The use of a perfusion model for studying aggregation and attachment of platelets and tumor cells at subendothelial surfaces. 711 4

Ovarian cyst fluid has been a valuable source of the mucins (traditionally termed "blood group substances") that were used for the elucidation of the structures of the ABO Lewis blood group determinants, but the identity of the mucin peptide core(s) carrying these carbohydrate specificities is not known. An ovarian cyst fluid mucin was purified, deglycosylated with HF and digested with trypsin or chymotrypsin to yield a number of peptides. Amino acid sequencing of these peptides yielded five different sequences which showed complete or partial homology to the MUC-6 apomucin deduced from DNA sequencing. As no other sequences were identified, it is concluded that MUC-6 is the major mucin core structure of ovarian cyst fluid mucin.
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PMID:MUC-6 mucin is a major component of "blood group substance" from human ovarian cyst fluid. 1077 94