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E Dodson

Publications and source records attributed to E Dodson.

26 records · Page 2Linked to original sources
PubMed1989

High-resolution (1.5 A) crystal structure of phospholipase C from Bacillus cereus.

Both the phosphatidylinositol-hydrolysing and the phosphatidylcholine-hydrolysing phospholipases C have been implicated in the generation of second messengers in mammalian cells. The phosphatidylcholine-hydrolysing phospholipase C (PLC) from Bacillus cereus, a monomeric protein containing 245 amino-acid residues, is similar to some of the corresponding mammalian proteins. This, together with the fact that the bacterial enzyme can mimic the action of mammalian PLC in causing, for example, enhanced prostaglandin biosynthesis, suggests that B. cereus PLC can be used as a model for the hitherto poorly characterized mammalian PLCs. We report here the three-dimensional structure of B. cereus PLC at 1.5 A resolution. The enzyme is an all-helix protein belonging to a novel structural class and contains, at least in the crystalline state, three Zn2+ in the active site. We also present preliminary results from a study at 1.9 A resolution of the complex between PLC and inorganic phosphate (Pi) which indicate that the substrate binds directly to the metal ions.

Bacillus cereus↗
PubMed1983

Insulin.

Explore the source record for details and available documents.

Amino Acid Sequence↗
PubMed1981

Evidence concerning insulin activity from the structure of a cross-linked derivative.

The important of crystallographic refinement for confident structural description, even at modest resolution, is demonstrated for N alpha A1,N epsilon B29-L,L-2,7-diaminosuberoyl (A2sb) insulin, a cross-linked insulin of low potency. The spatial arrangement of the cross-link itself can be described, and reliable estimates of the accuracy in atomic positions obtained. Comparison of invariant A2sb and native insulins shows a strong structural similarity, especially for the A chain surface residues and the dimer-forming residues of the B chain which have generally been strongly implicated in the receptor-binding region. Evidence from this analysis directs attention to the A chain, particularly the backbone, as being important in interactions with the membrane-bound receptor.

Animals↗
PubMedDate not supplied

Bonding of molecular oxygen to T state human haemoglobin.

Haemoglobin (Hb) is the tetrameric protein molecule that in vertebrate blood transports oxygen from the lungs to the tissues. This function depends on four subunits in the molecule binding cooperatively so that their affinity for oxygen increases as the level of oxygenation increases. X-ray analysis has shown that deoxyhaemoglobin, which has a low oxygen affinity, and oxyhaemoglobin, which has a high oxygen affinity, differ principally in their subunit or quaternary structures, referred to as the T and R states, respectively. As it switches from the T state to the R state during oxygenation, Hb increases its oxygen affinity. However, the structural pathway between deoxy- and oxy-haemoglobin is not known, principally because there has been no accurate structural knowledge of the intermediate states. We report here the crystal structure of T state human Hb in which the alpha chains are oxygenated and the beta subunits are oxygen-free. In this crystal the Hb appears to be in an intermediate state between the unliganded T state and the liganded R state. There is also evidence that the Hb molecule operates by loading and unloading the beta haems and thus the alpha-oxy, beta-deoxy Hb crystal may represent a physiologically important state.

Crystallography↗