High impact information on ALDH1A1

• Cytotoxicity was eliminated in the presence of catalase and aldehyde dehydrogenase (ALDH) [1].
• Identification of ALDH in amacrine cells provides additional evidence that cells of the inner retina are involved in retinoid metabolism [2].
• A class 1 aldehyde dehydrogenase (ALDH) catalyzes oxidation of retinaldehyde to retinoic acid in bovine retina [2].
• The majority of ALDH-positive cells were unreactive with antibodies against known amacrine cell enzymes and neurotransmitters, including GABA and glycine [2].
• In addition, a direct role for corneal ALDH as a UV-B photoreceptor in this anterior eye tissue has also been proposed (Abedinia et al. 1990) [3].

Biological context of ALDH1A1

• A dual role in protecting the eye against UV-B light is proposed--oxidation of aldehydes generated by light induced lipid peroxidation, and the direct absorption of UV-B light by bovine corneal ALDH [4].
• A didelphid marsupial, the gray short-tailed opossum (Monodelphis domestica), was used as a model species to study the biochemical genetics of alcohol dehydrogenases (ADHs) and aldehyde dehydrogenase (ALDH) in corneal tissue [3].
• Isoelectric point variants of corneal ALDH (designated ALDH3) and a major soluble protein in corneal extracts were observed among eight families of animals used in studying the genetics of these proteins [3].
• Two helices and one surface loop that line the tunnel are likely to have a key role in defining substrate specificity in the wider ALDH family [5].
• All-trans retinal fits into the active-site pocket of ALDH1, but not into the pocket of ALDH2 [5].

Anatomical context of ALDH1A1

• The ALDH-positive amacrine cells in bovine retina are novel, being limited in distribution to the dorsal retina and unlabeled with other amacrine cell-specific markers [2].

Associations of ALDH1A1 with chemical compounds

• Aldehyde dehydrogenase (ALDH) is the major enzyme involved in the oxidation of acetaldehyde [6].
• The ALDH-positive amacrine cells also did not react with anti-cellular retinoic acid-binding protein, which was present in a subset of GABA-positive amacrine cells [2].
• When comparing substrate specificity between human and bovine corneal ALDH, using NADP as coenzyme, it was shown that the human enzyme preferred benzaldehyde whereas the bovine enzyme revealed the strongest enzymatic activity with hexanal [7].
• The relative sizes of the tunnels also suggest why the bulky alcohol aversive drug disulfiram reacts more rapidly with ALDH1 than ALDH2 [5].
• Alkaline hydrolysis of (3)H-labeled ALDH-1 released most of the radiolabel as compounds much more polar than cholesterol [8].

Other interactions of ALDH1A1

• The ALDH1 enzyme had a pI of 7.45 and exhibited a low Km (6.37 microM) for retinal, while the ALDH2 enzyme was found to have very low Km for acetaldehyde (0.98 microM) [9].

Analytical, diagnostic and therapeutic context of ALDH1A1

• The pattern of ALDH expression in fetal bovine retinas was documented by immunocytochemistry [2].
• In flat-mounted retinas processed by in situ hybridization, the larger ALDH-positive amacrine cells tended to be more heavily labeled [2].
• The data provided evidence for genetic identity of corneal ALDH with this major soluble protein, and supported biochemical evidence, recently reported for purified bovine corneal ALDH, that this enzyme constitutes a major portion of soluble corneal protein (Abedinia et al. 1990) [3].
• The identity was confirmed by immunoprecipitation with antiserum to ALDH-1 [8].
• MALDI-MS analysis of both proteins recovered from duplicate gels indicated both to be aldehyde dehydrogenase class 1 (ALDH-1) [8].

References