Identification of the reactive sulphydryl group of mitochondrial aspartate aminotransferase from pig heart

Doonan, Shawn; Stanway, Glyn

doi:10.1016/0014-5793(76)80700-4

Cited by 3 publications

(1 citation statement)

References 15 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other regions of relatively great dissimilarity occur between, for example, residues 122 to 156 (eight identities, 2376; this region contains a substantial number of deletions in the mitochondrial isozyme) and 163 to 187 (seven identities, 28%). It is worth noting that the latter region of the mitochondrial isozyme contains the single cysteine (1 66) claimed to be syncatalytically modified by N-ethylmaleimide [37] ; a different unique cysteine residue (80) is modified by iodoacetic acid [38]. Recent work [lo] has shown that selective permeation of rat liver mitochondrial aspartate aminotransferase into mitochondria is inhibited by blocking a single reactive cysteine in the protein.…”

Section: Comparison Of the Pritnmy Structures Of The Cytosolic And MImentioning

confidence: 99%

The Cytosolic and Mitochondrial Aspartate Aminotransferases from Pig Heart. A Comparison of their Primary Structures, Predicted Secondary Structures and Some Physical Properties

Barra¹,

Bossa²,

Martini³

et al. 1980

Eur J Biochem

Self Cite

View full text Add to dashboard Cite

1.A primary structure is presented for mitochondrial aspartate aminotransferase from pig heart based on previously published results [Barra et al. (1977) FEBS Lett. 83, 241 -244; ( 1 979 3. Hydrophobic chromatography of the isozymes using alkyl agaroses suggests that the cytosolic but not the mitochondrial isozyme has a hydrophobic patch or pocket capable of binding to the alkyl side chains of the affinity medium.4. Evidence is presented to show that the cytosolic isozyme contains some basic amino acids whose ionizations are not expressed under native conditions. The mitochondrial isozyme does not show this effect.5. Predictions of the secondary structures of the isozymes are presented based on four predictive models. Minimum predictions are derived on the basis of agreement of three out of four of the individual predictions. These agregate predictions underestimate the amount of ordered secondary structure in both isozymes and suggest a relatively low degree of similarity between the isozymes. Individual predictive models, on the other hand, reveal greater similarities in secondary structures between the two isozymes.Aspartate aminotransferase, in common with a small number of other enzymes, exists in two distinct molecular forms one associated with the cell cytosol and the other with the mitochondria [l-31. These two isozymes differ in chemical and physical properties (for a review, see [4]) and indeed it is now known that, in humans, they are coded by genes on different chromosomes (I. Craig, quoted in [5]). Some time ago we [6] and another group [7] reported the complete primary structure of the cytosolic isozyme from pig heart and it seemed logical to extend these investigations to the corresponding mitochondrial form in order to provide a basis for understanding the comparative enzymology, evolutionary history and compartmen-

show abstract

Section: Comparison Of the Pritnmy Structures Of The Cytosolic And MImentioning

confidence: 99%