Biomedical subjects

D J Strydom

Publications and source records attributed to D J Strydom.

52 records · Page 3Linked to original sources

PubMed1977

Homology of functionally diverse proteins.

Disulphide-rich proteins of widely differing functions were aligned with the aid of their half-cystinyl residues. This led to the grouping of ribonuclease, phospholipase A, lysozyme, snake venom toxins, bee and scorpion venom peptides, and the plant proteins potatoe carboxypeptidase inhibitor, ragweed pollen allergen, mistletoe toxins and pineapple sulfhydryl protease inhibitor into one super-family of proteins. Very few deletions/insertions were needed to effect alignment and probabilities were calculated for random occurrence of the matches that were found.

Allergens↗

PubMed1977

Snake venom toxins. The amino-acid sequence of a short-neurotoxin homologue from Dendroaspis polylepis polylepis (black mamba) venom.

The third most abundant component of black mamba venom, named FS2, was sequenced with the aid of sequenator studies and peptides derived by tryptic and chymotryptic digestion. Cyanogen bromide digests provided extra information to support the proposed structure. This protein is a homologue of the short neurotoxins of snake venom, but is much less toxic. Its structure is quite different from both neurotoxins and the other mamba proteins, called angusticeps types (neurotoxin homologues). Comparison of the known angusticeps-type toxins from mamba venom with mamba neurotoxins and each other leads to proposals that these proteins of low toxicity are inventions of the group of mambas and that three different, as yet unknown, functions will be associated with the three subgroups that are discernable.

Amino Acid Sequence↗

PubMed1977

Snake venom toxins. The amino acid sequence of toxin Vi2, a homologue of pancreatic trypsin inhibitor, from Dendroaspis polylepis polylepis (black mamba) venom.

The amino acid sequence of venom component Vi2, a protein of low toxicity from Dendroaspis polylepis polylepis venom was determined by automatic sequence analysis in combination with sequence studies on tryptic peptides. This protein, the most retarded fraction of this venom on a cation-exchange resin, is a homologue of bovine pancreatic trypsin inhibitor consisting of a single chain of 57 amino acid residues containing six half-cystine residues. The active site lysyl residue of bovine trypsin inhibitor is conserved in Vi2 although large differences are found in the rest of the molecule.

Amino Acid Sequence↗

PubMed1976

Snake venom toxins. Purification and properties of low-molecular-weight polypeptides of Dendroaspis polylepis polylepis (black mamba) venom.

Twelve low-molecular-weight proteins, of which eleven have subcutaneous LD50 values of less than 40 mug/g mouse, were purified from Dendroaspis polylepis polylepis venom. Ion-exchange chromatography on Amberlite CG-50 and ion-exchange chromatography on carboxymethyl-cellulose and/or phosphocellulose was used for the purification. The amino-terminal sequences of these proteins were determined and used to indicate that five groups of low-molecular-weight polypeptides are to be found in black mamba venom. Proteins from two of these groups which have low toxicity individually, when used together show synergism, in that their toxicity in combination is greater than the sum of their individual toxicities.

Amino Acid Sequence↗

PubMed1975