Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0393754 (HSA)
 2,996 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The administration of protein antigens into earthworms Lumbricus terrestris and Eisenia foetida induces the formation of antigen-binding protein (ABP) with the maximum response occurring between days 4 and 8. High proteolytic activities observed both in coelomocytes and in coelomic fluids cause rapid antigen degradation; the majority of antigen is digested during the first 24 h. To analyze the role of proteolytic processing of antigen in ABP response in vitro, the intact antigen (ARS-HSA) as well as its proteolytic fragments were added to tissue explant cultures and ABP formation followed by indirect ELISA using mAb to ABP. The response to small fragments was comparable to that induced by intact ARS-HSA. Furthermore, the response to intact antigen was almost completely blocked by the non-toxic serine protease inhibitor Pefabloc, while the response to small fragments was only slightly reduced. The kinetics of response to intact antigen significantly differed from that induced by small (< 3 kDa) fragments. We suggest that proteolytic processing is involved in the stimulation of ABP formation.
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PMID:Antigen processing in earthworms. 800 50

Expression of a functional antibody fragment (Fab) using an Escherichia coli cell-free expression system has been reported previously [Jiang et al., FEBS Lett., 514, 290-294 (2002)]. The low yield of the synthesized antibody, however, limits the usefulness of the cell-free expression system, partly due to the degradation of product by endogenous proteases from the E. coli extract. To determine which proteases are responsible for the degradation, we compared the expression of a 6D9 Fab fragment under conditions whereby several protease inhibitors were added into the cell-free system. The addition of serine protease inhibitor increased the amount of the Fab fragment, indicating that serine proteases caused the antibody degradation. Therefore, several serine protease-deficient mutants of E. coli BW25113 were constructed by targeted homologous recombination. The use of extract from a double protease-deficient mutant (DeltadegP-ompT) significantly increased the amount and antigen-binding activities of an anti-HSA scFv and a 6D9 Fab fragment. These results suggest that the DegP- and OmpT-deleted mutant is a useful source of S30 extract for the production or screening of antibodies using the cell-free expression system.
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PMID:Improvements in the cell-free production of functional antibodies using cell extract from protease-deficient Escherichia coli mutant. 1623 76