AASA

Stenklo K, HD Thorell, H Bergius, R Aasa, T Nilsson (2001) Chlorite dismutase from Ideonella dechloratans. J Biol Inorg Chem 6 601-607. 

For a balanced historical record I should add that the late W. E. Blumberg has been cited to state (W. R. Dunham, personal communication) that One does not need the Aasa factor if one does not make the Aasa mistake, by which Bill meant to say that if one simulates powder spectra with proper energy matrix diagonalization (as he apparently did in the late 1960s in the Bell Telephone Laboratories in Murray Hill, New Jersey), instead of with an analytical expression from perturbation theory, then the correction factor does not apply. What this all means I hope to make clear later in the course of this book. 

Lundin, A. and Aasa, R. 1973. A simple device to maintain temperatures in the range 4.2-100 K for EPR measurements. Journal of Magnetic Resonance 8 70-73. 

Karlsson BG, Aasa R, Malmstrdm BG, Lundberg LG (1989) FEBS Lett 253 99... 

AASA a-aminoadipic semialdehyde, AdoHcy S-adenosylhomocysteine, AdoMet S-adenosylmethionine, Ala alanine, Arg arginine, alle alloisoleucine, Apo aminopiperidone, ASA argininosuccinate,... 

Pipecolic acid Peroxisomal disease AASA dehydrogenase deficiency Hyperlysinemia ... 

The essential amino acid lysine (2,5-diaminohexanoic acid) can be degraded via two pathways, viz. the so-called saccharopine pathway and the pipecolic acid (PA) pathway. Both pathways merge at the level of a-aminoadipic acid semialdehyde (AASA). It is generally accepted that the saccharopine pathway constitutes the major breakdown pathway. However, the PA pathway has attracted much attention since the discovery of the association between the presence of elevated PA levels and Zellweger syndrome almost 40 years ago. Mainly because the analysis of amino acids was the primary biochemical approach for studying presumed inborn errors of metabolism, PA in Zellweger syndrome was discovered even before it was realized that this disorder was based on a defect of peroxisomal functions. 

The availability of stable isotope-labeled PA makes an accurate quantitative determination of this imino acid possible. A short high-performance liquid chromatography (HPLC) run prior to the mass spectrometer inlet will result in a discrete peak of PA. For the definitive diagnosis of AASA dehydrogenase deficiency, a simultaneous determination of AASA would be preferred. The absence of a commercially available labeled standard leaves this analysis in the experimental stage. 

AASA dehydrogenase deficiency (pyridoxine-responsive convulsions). 

PA is secondarily increased in AASA dehydrogenase deficiency and may be an important diagnostic criterium. The primary accumulating AASA - the toxic substance inactivating pyridoxine - is still difficult to analyze. 

PA reference values for plasma, urine, and CSF are 2.511.25 pmol/1, 0-6 mmol/ mol creatinine, and <0.12 pmol/1, respectively. Pathological values may cover a very wide range as an example, patients with the Zellweger syndrome may have plasma PA levels up to 170 pmol/1 the CSF of a AASA-dehydrogenase-deficient patient may show PA levels as high as 3 pmol/1. 

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