α酸化

WordNet

first in order of importance; "the alpha male in the group of chimpanzees"; "the alpha star in a constellation is the brightest or main star"
the 1st letter of the Greek alphabet
the beginning of a series or sequence; "the Alpha and Omega, the first and the last, the beginning and the end"--Revelations
early testing stage of a software or hardware product; "alpha version"
the process of oxidizing; the addition of oxygen to a compound with a loss of electrons; always occurs accompanied by reduction (同)oxidization, oxidisation
any high mountain

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アルファ(ギリシア語アルファベットの第1字A,α;英語のA,aに相当) / アルファ星(星座の主星)
酸化
高山,高峰

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/05/25 16:18:30」(JST)

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Enzymatic steps of alpha oxidation

Alpha oxidation (α-oxidation) is a process by which certain fatty acids are broken down by removal of a single carbon from the carboxyl end. In humans, alpha-oxidation is used in peroxisomes to break down dietary phytanic acid, which cannot undergo beta-oxidation due to its β-methyl branch, into pristanic acid. Pristanic acid can then acquire acetyl-CoA and subsequently become beta oxidized, yielding propionyl-CoA.

Pathway

Alpha-oxidation of phytanic acid is believed to take place entirely within peroxisomes.

Phytanic acid is first attached to CoA to form phytanoyl-CoA.
Phytanoyl-CoA is oxidized by phytanoyl-CoA dioxygenase, in a process using Fe²⁺ and O₂, to yield 2-hydroxyphytanoyl-CoA.
2-hydroxyphytanoyl-CoA is cleaved by 2-hydroxyphytanoyl-CoA lyase in a TPP-dependent reaction to form pristanal and formyl-CoA (in turn later broken down into formate and eventually CO₂).
Pristanal is oxidized by aldehyde dehydrogenase to form pristanic acid (which can then undergo beta-oxidation).

(Propionyl-CoA is released as a result of beta oxidation when the beta carbon is substituted)

Deficiency

Enzymatic deficiency in alpha-oxidation (most frequently in phytanoyl-CoA dioxygenase) leads to Refsum's disease, in which the accumulation of phytanic acid and its derivatives leads to neurological damage. Other disorders of peroxisome biogenesis also prevent alpha-oxidation from occurring.

References

Casteels, M; Foulon, V; Mannaerts, GP; Van Veldhoven, PP (2003), "Alpha-oxidation of 3-methyl-substituted fatty acids and its thiamine dependence", European journal of biochemistry / FEBS 270 (8): 1619–1627, doi:10.1046/j.1432-1033.2003.03534.x, PMID 12694175
Quant, Patti A.; Eaton, Simon, eds. (1999), Current views of fatty acid oxidation and ketogenesis : from organelles to point mutations 466 (2nd ed.), New York, NY: Kluwer Acad./Plenum Publ., pp. 292–295, ISBN 0-306-46200-1

UpToDate Contents

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English Journal

Engineering Saccharomyces cerevisiae to produce odd chain-length fatty alcohols.

Jin Z1,2,3,4, Wong A3,4, Foo JL3,4, Ng J3,4, Cao YX1,2, Chang MW5,6, Yuan YJ7,8.
Biotechnology and bioengineering.Biotechnol Bioeng.2016 Apr;113(4):842-51. doi: 10.1002/bit.25856. Epub 2015 Nov 2.
Fatty aldehydes and alcohols are valuable precursors used in the industrial manufacturing of a myriad of specialty products. Herein, we demonstrate the de novo production of odd chain-length fatty aldehydes and fatty alcohols in Saccharomyces cerevisiae by expressing a novel biosynthetic pathway inv
PMID 26461930

Safety of long-term restrictive diets for peroxisomal disorders: vitamin and trace element status of patients treated for Adult Refsum Disease.

Baldwin EJ1, Harrington DJ2, Sampson B3, Feher MD1, Wierzbicki AS1,4.
International journal of clinical practice.Int J Clin Pract.2016 Mar;70(3):229-35. doi: 10.1111/ijcp.12770. Epub 2016 Jan 22.
BACKGROUND: Adult Refsum's Disease (ARD) is caused by defects in the pathway for alpha-oxidation of phytanic acid (PA). Treatment involves restricting the dietary intake of phytanic acid by reducing the intake of dairy-derived fat. The adequacy of micronutrient intake in patients with ARD is unknown
PMID 26799636

[Hereditary peroxisomal diseases].

Astudillo L1, Sabourdy F2, Touati G3, Levade T4.
Presse médicale (Paris, France : 1983).Presse Med.2016 Mar;45(3):302-12. doi: 10.1016/j.lpm.2015.05.009. Epub 2016 Feb 18.
Peroxisomes are small intracellular organelles that catalyse key metabolic reactions such as the beta-oxidation of some straight-chain or branched-chain fatty acids and the alpha-oxidation of phytanic acid. These enzyme reactions produce hydrogen peroxide, which is subsequently neutralized by the pe
PMID 26899150