Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ability of the alternative pathway of complement to discriminate targets as either activators or non-activators is mediated by different binding properties of factor H to surface-associated C3b molecules. In the present study we have probed the interaction between H and C3b using five anti-H mAb. The binding sites of the mAb were mapped by Western blotting using both recombinant and trypsin-generated H fragments. Two mAb bound to CCP1 (90X, 196X), two to CCP5 (MRC OX24, 86X) and one to CCP8-15a (131X). At a molar ratio 2:1 of 125I-H:mAb all tested mAb enhanced binding of H to both activator- and non-activator-bound C3b. At higher concentrations two mAb had an inhibitory effect on H binding to surface-associated C3b (OX24, 131X). Thus the mAb 131X inhibits H binding to surface-bound C3b but unlike OX24 it does not bind to the previously described C3b binding site within or near CCP4-5. These results indicate that there is an additional interaction site on factor H for surface-bound C3b.
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PMID:Analysis of the recognition mechanism of the alternative pathway of complement by monoclonal anti-factor H antibodies: evidence for multiple interactions between H and surface bound C3b. 881 8

The crystal structure of a bifunctional inhibitor of alpha-amylase and trypsin from the seeds of ragi (Indian finger millet, Eleusine coracana Gaertneri) has been determined by an X-ray diffraction method. The inhibitor consists of 122 amino acids with five disulfide bridges and belongs to the plant alpha-amylase/trypsin-inhibitor family. This is the first crystal structure determination of a member of this family. The protein, purified from the seeds of ragi, has a molecular mass of 13300 Da with a pI of 10.3. Crystals were grown by a microdialysis method using ammonium sulfate as precipitant. The improved purification protocol and the modified crystallization conditions enabled reproducible growth of the crystals. The cell parameters are a = 41. 2, b = 47.4, c = 55.9 A. The intensity data were collected to 2.9 A resolution, and the crystal structure was determined using the molecular-replacement method. The structure was refined using the X-PLOR and CCP4 program packages to a conventional R factor of 21%. The structure contains four alpha-helices between residues 19-29, 37-51, 56-65 and 90-95, and two short antiparallel beta-strands between residues 67-70 and 73-75.
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PMID:Structure of the bifunctional inhibitor of trypsin and alpha-amylase from ragi seeds at 2.9 A resolution. 1008 91