Characterization of a bifunctional wheat inhibitor of endogenous α-amylase and subtilisin

A bifunctional α-amylase/serine protease inhibitor which inhibits germination-specific cereal α-amylases of the Graminae subfamily Festucoideae as well as bacterial subtilisins has been isolated from wheat grains. This protein has M_r ≈20500 and pI ≈7.2. The amino acid composition and N-teminal sequence (45 residues) show that the inhibitor is homologous with cereal and leguminous inhibitors of the soybean trypsin inhibitor (Kunitz) family.     

High productivity by Fish Eagles on a polluted dam near Harare

Mundy, P.J. & Couto, J.T. 2000. High productivity by Fish Eagles on a polluted dam near Harare. Ostrich 71 (1 & 2): 11–14.

Lake Chivero, in the Robert McIlwaine Recreational Park west of Harare, is the capital city's main reservoir of drinking water. It has been the subject of five surveys for pesticides and/or heavy metals in the period 1974–1995. The (geometric) average DDE residue level in seven Fish Eagle eggs collected in 1980 was 53 ppm dry weight. By 1995, DDT levels had considerably declined. There are now five pairs of Fish Eagles on Lake Chivero (1996), at a very low density of 14.8 km shoreline per pair. In the 14-year period, 1984–1997, 40 pair-occupations have been found and inspected, which produced 64 fledglings. One nest had fledglings in 11 years, and on three occasions broods of three were produced from it. A fourth brood of three was produced at another nest. The dam receives treated sewage effluent from the city and is now highly eutrophic; this has contributed to the eagles' breeding performance.     

Assembly of the RAG1/RAG2 Synaptic Complex

Assembly of antigen receptor genes by V(D)J recombination requires the site-specific recognition of two distinct DNA elements differing in the length of the spacer DNA that separates two conserved recognition motifs. Under appropriate conditions, V(D)J cleavage by the purified RAG1/RAG2 recombinase is similarly restricted. Double-strand breakage occurs only when these proteins are bound to a pair of complementary signals in a synaptic complex. We examine here the binding of the RAG proteins to signal sequences and find that the full complement of proteins required for synapsis of two signals and coupled cleavage can assemble on a single signal. This complex, composed of a dimer of RAG2 and at least a trimer of RAG1, remains inactive for double-strand break formation until a second complementary signal is provided. Thus, binding of the second signal activates the complex, possibly by inducing a conformational change. If synaptic complexes are formed similarly in vivo, one signal of a recombining pair may be the preferred site for RAG1/RAG2 assembly.