Structure, Biochemical Role and Importance of Carboxylase Class Enzymes in Metabolism

Öz

Cells, the smallest structures showing the structural and functional characteristics of a living being, obtain their biomass from inorganic carbon. Metabolites involved in central carbon metabolism are utilised within the TCA cycle for numerous biosynthetic purposes, such as synthesizing amino acids and fatty acids. To replenish the intermediates of the TCA, many organisms use anaplerotic reactions, usually involving enzymes such as pyruvate carboxylase, glutamate dehydrogenase, PEP carboxylase, and transaminase reactions. Carboxylases are important in fatty acids, amino acids, carbohydrate metabolism, polyketide biosynthesis, urea utilisation, and other cellular processes. Acetyl-CoA carboxylase, propionyl-CoA carboxylase, 3-methylcrotonyl-CoA carboxylase, and pyruvate carboxylase are carboxylase group enzymes that have been studied, and their roles in metabolism are well known. As a result of a problem in the production of enzymes involved in metabolism or a situation that prevents them from fulfilling their catalytic activities, abnormal and harmful organic acid metabolites accumulate in the cell. In metabolism, differential diagnoses are important to determine enzyme deficiencies and/or the determination of the catalytic activity of the relevant enzyme. Diagnosis of enzyme deficiencies can be made by genetic, biochemical, imaging, and molecular methods. It should be considered that these enzymes, whose catalytic activities are examined only in a few rare diseases, may be one of the underlying causes of diseases that occur in the metabolic process. Therefore, developing highly accurate, cost-effective, and reproducible methods for analyzing carboxylase group enzymes will greatly benefit patients in terms of the treatment process.

Anahtar Kelimeler

• Acetyl-CoA carboxylase
• propionyl-CoA carboxylase
• 3-methylcrotonyl-CoA carboxylase
• pyruvate carboxylase
• Biochemistry
• Metabolism

Karboksı̇laz Sınıfı Enzı̇mlerı̇n Yapısı, Bı̇yokı̇myasal Rolü ve Metabolı̇zmadakı̇ Önemı̇

Öz

Organizmalar, tüm hücre biyokütlesini heterotrofik ve ototrofik yollar ile inorganik karbondan (CO2) elde ederler. Merkezi karbon metabolizmasında yer alan metabolitler amino asitler ve yağ asitlerinin sentezi gibi çok sayıda biyosentetik amaçlar için TCA döngüsünden kullanılır. TCA döngüsünün ara maddelerini yeniden doldurmak için, birçok organizma genellikle piruvat karboksilaz, glutamat dehidrogenaz, PEP karboksilaz, glutamat dehidrogenaz, transaminaz tepkimeleri gibi bir karboksilasyon reaksiyonu kullanan anaplerotik reaksiyonlardan yararlanır. Doğada yaygın olarak bulunan karboksilazlar yağ asitleri, amino asitler, karbohidrat metabolizmasında, poliketid biyosentezinde, üre kullanımında ve diğer hücresel süreçlerde önemli rollere sahiptirler. Asetil-CoA karboksilaz (ACC), propiyonil-CoA karboksilaz (PCC), 3-metilkrotonil-CoA karboksilaz (MCC) ve piruvat karboksilaz (PC) çalışılmış ve metabolizmadaki rolleri bilinen karboksilaz grubu enzimlerdir. Metabolizmada görevli enzimlerin üretilmesinde bir sorun veya katalitik aktivitelerini yerine getiremesine engel bir durumun oluşması sonucunda hücre içersinde anormal ve zararlı organik asit metabolitlerinin birikimi söz konusu olmaktadır. Metabolizmada enzim eksiklikleri ve/veya ilgili enzime ait katalitik aktivite tayinini belirlemek için ayırıcı tanılar önem arz etmektedir. Enzim eksikliklerinde tanı genetik, biyokimyasal, görüntüleme ve moleküler yöntemler ile konulabilmektedir. Sadece bazı nadir hastalıklarda katalitik etkinlikleri incelenen bu enzimlerin metabolik süreçte meydana gelebilecek hastalıkların altında yatan sebeplerden biri olabileceği göz önünde bulundurulmalıdır. Bu nedenle karboksilaz grubu enzimlerin analizlerine yönelik geliştirilecek doğruluğu yüksek, uygun maliyetli ve tekrarlanabilir analiz metodları hastaların tedavi süreci açısından büyük fayda sağlayacaktır.

Anahtar Kelimeler

• Asetil-CoA karboksilaz
• propiyonil-CoA karboksilaz
• 3-metilkrotonil-CoA karboksilaz
• piruvat karboksilaz
• Biyokimya
• Metabolizma

Kaynakça

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