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Biomedical subjects

K S Cheah

Publications and source records attributed to K S Cheah.

At least 73 records · Page 4Linked to original sources
PubMed1979

Mitochondrial calcium efflux and porcine stress-susceptibility.

Mitchondrial Ca2+ efflux rates of M. longissimus dorsi correlate very closely with parameters associated with porcine stress-susceptibility. Experimental data support the measurement of mitochondrial Ca+2 efflux to be a very sensitive and reliable method for differentiating porcine stress-susceptibility.

Animals↗
PubMed1979

Translation of embryonic-chick tendon procollagen messenger ribonucleic acid in two cell-free protein-synthesizing systems.

Embryonic-chick tendon poly(A)-containing RNA was translated in the wheat-germ and mRNA-dependent rabbit reticulocyte-lysate systems. The ability of each system to synthesize polypeptides similar to pro-alpha chains of collagen was tested on the bases of electrophoretic mobility and susceptibility to highly purified bacterial collagenase. Very small amounts of polypeptides in the size range of pro-alpha chains were synthesized in the wheat-germ system, whereas efficient synthesis of two polypeptides similar to pro-alpha1 and pro-alpha2 chains was achieved in the reticulocyte lysate. The collagenous nature of the major high-molecular-weight products synthesized was demonstrated by their susceptibility to collagenase and ability to act as a substrate for purified collagen proline hydroxylase. Determinations of the relative amounts of these translation products suggest that the 2:1 ratio of pro-alpha1 and pro-alpha2 chains found in type I procollagen is reflected in proportional amounts of translatable mRNA for pro-alpha1 and pro-alpha2 chains. Comparisons of the electrophoretic mobilities of hydroxylated and unhydroxylated reticulocyte-lysate translation products were made with appropriate standards of hydroxylated and unhydroxylated procollagen polypeptides. The results suggest that, in common with a number of secreted proteins, procollagen is synthesized as pre-pro molecules consistent with the ;Signal Hypothesis'.

Animals↗
PubMed1977

Analysis of nucleosomal deoxyribonucleic acid in a higher plant.

Comparisons of nuclease digestions of chromatin in nuclei from rye embryos and rat liver show that their nucleosomal DNA is similar, i.e. DNA subunits consist of 200 base-pair repeats with 140 base-pair cores of identical substructure. The identical nucleosome structure is present in nuclei from cells of rye embryos that have been non-viable (i.e. dead) for more than 7 years. These findings indicate a high degree of stability of the DNA-histone complex and are consistent with conservation of the nucleosomal structure of chromatin during evolution.

Base Sequence↗
PubMed1975

Properties of Ascaris muscle mitochondria. 1. Cytochromes.

1. The cytochrome system in Ascaris muscle mitochondria was further characterized using purer preparations. 2. Difference spectra (at 22 degrees C and -196 degrees C) of the mitochondrial preparations using succinate and ascorbate plus N,N,N' ,N'-tetramethyl-p-phenylenediamine show that Ascaris muscle mitochondria contain cytochromes c1, c and aa3, and also at least three b-type cytochromes. The b-type cytochrome is the predominant component. 3. Cytochrome c and Ascaris cytochrome b-560 can be extracted from the mitochondrial preparations with 150mM KCl, leaving the membrane-bound cytochromes c1, b and aa3 in the KCl residue.

Animals↗