No abstract

Thiol compounds have been investigated as inhibitors of the covalent binding reaction of human complement protein C4 using Sepharose-C1s as a combined activating and binding surface. o- and p-substituted aminothiophenols are equally effective inhibitors, whereas the m-substituted compound is a less potent inhibitor. The anti-hypertensive drug captopril is also shown to inhibit the covalent binding reaction. A comparison of the effects of these compounds on the covalent binding reaction of isolated C4A and C4B has been made. Results suggest that a Pro-to-Leu substitution in C4B is likely to account for the differences in inhibitory potency of C4B compared with C4A observed with the aromatic inhibitors.

A stable L‐form of Aeromonas salmonicida, which resulted from induction with benzylpenicillin, grew on brain heart infusion agar at 0–5°C. The L‐form was stored successfully for 10 months in phosphate‐buffered saline supplemented with 150 g l‐1 glycerol at ‐70°C. Reversion of the L‐form to parental‐type walled cells was achieved by transfer to brain heart infusion broth with incubation at 25°C.

A stable L-form of Aeromonas salmonicida, which resulted from induction with benzylpenicillin, contained more of an outer membrane protein, with an estimated molecular weight of 40 kDa but less of 47.9 and 38 kDa proteins, than did parental walled cells. In addition, from Western blots, two protein bands reacted strongly with a polyclonal antiserum. The antiserum did not react demonstrably with the band detected in the L-forms on the gels.

Biochemical Society Transactions ( 1 994) 22 85s Structural investigation of the thiolester-forming region of human complement component C4.Human complement component C 4 is a thiolester-forming member of the a-macroglobulin family [I]. During activation of the classical complement cascade, the a-chain of C4 is cleaved by complement component CIS, which releases the anaphylatoxin C4a and exposes