PubMed Health⌕ Search

Biomedical subjects

H Kruger

Publications and source records attributed to H Kruger.

At least 37 records · Page 2Linked to original sources
PubMed1982

Configuration assignments of the amino acid residues and the presence of N-methyldehydroalanine in toxins from the blue-green alga, Microcystis aeruginosa.

The configuration assignment of the alpha-carbon atom of amino acid residues in four toxin variants from Microcystis aeruginosa have been made by stereospecific enzymic transformations. The relative conformation assignment of the beta-carbon atom of beta-CH3-aspartic acid could be made by comparison of the electrophoretic mobility with literature values reported for the authentic compound. The presence of an N-methyldehydroalanine residue, which, due to elimination of methylamine under hydrolytic conditions, previously escaped detection by conventional means, has been confirmed by identification of N-methylalanine in the hydrolysate after reduction of toxin with sodium borohydride.

Alanine↗
PubMed1982

Isolation and amino acid sequence of caudoxin, a presynaptic acting toxic phospholipase A2 from the venom of the horned puff adder (Bitis caudalis).

A presynaptic acting toxic phospholipase A2, designated caudoxin, was purified from the venom of Bitis caudalis by a combination of gel filtration and ion-exchange chromatography. The specificity of the enzyme was shown to be of the A2 type. The enzyme contains 121 amino acid residues in a single chain and is cross-linked by seven disulfide bridges. Application of cyanogen bromide cleavage and digestion with trypsin and chymotrypsin yielded peptides providing the necessary overlaps to complete derivation of the sequence. Structural features of caudoxin in relation to other toxic and non-toxic phospholipases A2 are discussed.

Amino Acid Sequence↗
PubMed1979

Purification, some properties and the complete primary structures of two protease inhibitors (DE-3 and DE-4) from Macrotyloma axillare seed.

The Macrotyloma axillare plant, belonging to the Leguminosae family, is a perennial climbing or trailing herb 0.2--3.5 m long. The plant is indigenous to South Africa and it occurs in the warm dry northern parts of the Transvaal. It has been introduced into Australia, where the seed are used as animal food. Two protease inhibitors, DE-3 and DE-4, were purified from Macrotyloma axillare seed by gel filtration on Sephadex G-50 followed by ion-exchange chromatography on DEAE-cellulose. They each comprise 76 amino acid residues including 14 half-cystine residues. The complete primary structures of the two protease innibitors have been elucidated and their sequences are 67% identical. The inhibitor specificities, the sequences, the invariant amino acid residues and the reactive inhibitor sites of protease inhibitors DE-3 and DE-4 resemble the corresponding properties of the Bowman-Birk double-headed protease inhibitor group. The cysteine residues are in similar locations to those in protease inhibitors of known structure so they are presumed to link similarly.

Amino Acid Sequence↗
PubMed1975

Serum transferrin values in White and Black toddlers: a comparative study.

Serum albumin and transferrin levels were measured and compared in healthy White and Black toddlers and a significant difference was found. Black girls had significantly higher transferrin levels than White girls. No significant correlation was found between serum transferrin and either body weight, haemoglobin or serum albumin. These findings seem to question the validity of transferrin as a sensitive parameter for the detection of subtle protein energy malnutrition.

Black or African American↗
PubMed1969

RBE values for fast neutrons in connection with estimates of the radiation burden in space.

Much data concerning radiation in space as a serious danger to astronauts can be obtained in laboratories on Earth. For different parameters we investigated the relative biological efficiency (RBE) of 14-MeV neutrons on mice, rats and guinea pigs (being wholly exposed). Also the mitosis inhibition for isolated cells was determined. The RBE values found were: for lethality in the LD50(30d)-region--about 2 (for mice, rats and guinea pigs); for reduction due to radiation of living weight of different animals--2 to 3; for reduction of small gut weight of rats and guinea pigs--2.5 and 2; for histological changes in blood and albumin serum (rats and guinea pigs)--about 2; for the highly sensible cells of the lense epithelium from eyes of rabbits--2.5; for the mitosis inhibition of HeLa cells--2.5. The apparatus for radiation tests is described and measuring methods are indicated. The radiation of the whole body of mice, rats and guinea pigs was determined by activating of MgCl2 solution filled into phantoms. By means of a computer, the depth-dose curve can be determined for larger biological objects.

Animals↗