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Biomedical subjects

R M Pinto

Publications and source records attributed to R M Pinto.

At least 73 records · Page 4Linked to original sources
PubMed1983

Adenylosuccinate lyase from Artemia embryos. Purification and properties.

In crude extracts, the molecular form of adenylosuccinate lyase is pH-dependent as studied by gel filtration and sucrose gradient centrifugation. At pH values of 8.7 and 6.5, the enzyme exhibits molecular forms of 200 kDa and larger than 500 kDa, respectively. At pH values of 7.0-7.5, forms of intermediate molecular weight were detected. Interconversion among the different molecular forms of adenylosuccinate lyase was not achieved when the enzyme was subjected to two successive chromatographic steps on Sepharose CL-6B using elution buffers at two different pH values. A unique form of 200 kDa was observed, regardless of the pH of the buffer used, upon either gel filtration or sucrose gradient centrifugation in the presence of 1 M NaCl. The enzyme from Artemia cysts was purified to homogeneity. It had molecular mass of 200 kDa and gave a single band of 56 kDa upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The Km values for adenylosuccinate, AMP, and fumarate were 1, 36, and 350 microM, respectively. The enzyme exhibits a Uni Bi-ordered mechanism and is maximally active at a pH value of 8.0-8.5. For maximum activity, the enzyme requires an ionic strength equivalent to 80 mM KCI. The isoelectric point determined by chromatofocusing was 5.04.

Adenylosuccinate Lyase↗
PubMed1979

Schistosome motility in saline media.

The authors observed the motility of 1067 worms used as a biological parameter indicating the vitality of the parasites, to define the survival time of S. mansoni males and females in 0,85% NaCl and PBS. Among the worms observed in 0,85% NaCl the mean time of survival in minutes was 204 for males and 240 for females and in PBS it was 267 min. for males and 344 min. for females. All the tested differences (media, sex; sex for saline group; sex for PBS group) were significant at a 0.0001 level.

Animals↗