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Biomedical subjects

L Ossola

Publications and source records attributed to L Ossola.

24 records · Page 2Linked to original sources
PubMed1978

Purification and properties of two succinate semialdehyde dehydrogenases from human brain.

In human brain there are two major isoenzymes of succinate semialdehyde dehydrogenase (succinate-semialdehyde: NAD+ oxidoreductase, EC 1.2.1.24). They are composed of two apparently identical subunits with a molecular weight of 69 000. The Km (limits) for their substrates NAD+ and succinate semialdehyde are 1.6.10(-5) M and 3.7.10(-6) M, respectively, for one enzyme, and 1.85.10(-5) M and 2.10(-6) M, respectively, for the other. These values, and other kinetic data obtained from the two enzymes are not very different. However the enzymes differ in the following respects: their behavior on ion exchange and 5'-AMP affinity columns, their isoelectric points, their tryptic fingerprints and in their amino acid compositions.

Aldehyde Oxidoreductases↗
PubMed1978

Purification and some properties of L-glutamate decarboxylase from human brain.

Glutamate decarboxylase (EC 4.1.1.15) from human brain has been purified 8000-fold with respect to the initial homogenate. The molecular weight of the native enzyme was found to be 140000 by electrophoresis on a polyacrylamide gradient gel slab. The presence of a single protein band (Mr 67000) on sodium dodecylsulphate/polyacrylamide gel and the existence of only one N-terminal amino acid suggest that the enzyme consists of two similar if not identical polypeptide chains. The Km of the enzyme at the optimum pH of 6.8 is about 1.3 x 10(-3) M for glutamate and 0.13 x 10(-6) M for pyridoxal phosphate. The analysis of the effects of various inhibitors of mouse brain glutamate decarboxylase on the human enzyme confirms the strong competitive inhibition caused by 3-mercaptopropionic acid (Ki = 2.7 x 10(-6) M) while the Ki values for allylglycine and chloride ion are 1.8 x 10(-2) M and 2.2 x 10(-2) M, respectively.

Amino Acids↗
PubMed1977

[Purification of the glutamate decarboxylase from human brain].

A method of purifying the glutamate decarboxylase from human brain is described. The enzyme was purified 8 000 fold in regard to the initial homogenate and appears homogenous by electrophoresis, both in denaturing and non-denaturing conditions. The molecular weight of the native enzyme and its subunits indicate that GAD from human brain is formed by two similar if non identical polypeptide chains. The Km for glutamate and pyridoxal phosphate found for the human enzyme, respectively 1,2.10(-3) M and 0,13.10(-6) M, are close to the Km found for the Mouse enzyme.

Brain↗