Sitokrom p450 monooksijenaz enzim sistemleri
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Dosyalar
Tarih
1996
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
İnönü Üniversitesi Tıp Fakültesi Dergisi
Erişim Hakkı
info:eu-repo/semantics/openAccess
Özet
Sitokrom P450 (CYP450) monooksijenaz enzim sistemleri, matür eritrosit ve iskelet kası hücreleri dışında tüm memeli hücre tiplerinde ve prokaryotlarda bulunan hem-protein ailesidir. Bu enzimler, yapısal olarak farklı çeşitli bileşiklerin oksidasyonunu katalize ederler. Endojen sentezlenen bir çok bileşik, CYP450 enzimlerinin substratı olarak görev yapar. Bu bileşikler: prostaglandin ve lökotrienler dahil yağ asitleri, steroidler, yiyecek katkı maddeleri ve ilaçlar yanında besinlerle, enjeksiyonla, havadan inhalasyonla ya da deriden absorbsiyonla vücuda giren endüstriyel maddelerdir. Sitokrom P450 enzimleri, ilaç biyotransformasyonu ve metabolizması için en önemli sistemlerden biridir. Bu sistem indüksiyon veya inhibisyon gibi sayısız mekanizmalarla değişime uğrayabilir ve bireyler arasında oldukça farklı formları ortaya çıkabilir. CYP450 enzimleri, 400-530 amino asitten yapılı proteinlerdir. Baz dizilimi benzerliklerine göre, P450 sistemi 40 farklı aile içinde sınıflandırılır. CYP450 sisteminin tıpta çok önemli etkileri vardır: Bunlar; a) terapötik maddeleri inaktive veya aktive etme, b) kimyasal maddeleri oldukça yüksek derecede reaktif moleküllere dönüştürme ve istenmeyen hücre hasarı, hücre ölümü veya mutasyon gibi olaylara neden olma, c) steroid hormon sentezindeki bazı adımlara katılma ve d) yağ asidi ve bunların derivelerinin metabolizması gibi olaylardır.
The term cytochrome P450-containing monooxygenase enzyme systems refers to a family of heme proteins present in all mammalian cell types, except mature red blood cells and skeletal muscle cells, which catalyze the oxidation of a wide variety of structurally diverse compounds. Cytochrome P450 also occurs in procaryotes. Substrates for these enzyme systems include endogenously synthesized compounds such as steroids, fatty acids (including prostaglandins and leukotrienes), and compounds such as drugs, food additives, or industrial byproducts that enter the body through food sources, injection, inhalation from the air, or absorption through the skin. Drug biotransformation by cytochrome P-450 enzymes is one of the most important systems for drug metabolism. This system can be altered by a number of mechanisms, such as induction and inhibition, and can vary significantly among individuals. P450's are proteins of 400 to 530 aminoacids. Based on sequence similarities, P450's have been classified into about forty different families. The cytochrome P450 system has far reaching effects in medicine. It is involved in: (a) inactivation or activation of therapeutic agents, (b) conversion of chemicals to highly reactive molecules, which may produce unwanted cellular damage, cell death, or mutations, (c) participation in several steps in steroid hormone biosynthesis, and (d) metabolism of fatty acids and their derivatives.
The term cytochrome P450-containing monooxygenase enzyme systems refers to a family of heme proteins present in all mammalian cell types, except mature red blood cells and skeletal muscle cells, which catalyze the oxidation of a wide variety of structurally diverse compounds. Cytochrome P450 also occurs in procaryotes. Substrates for these enzyme systems include endogenously synthesized compounds such as steroids, fatty acids (including prostaglandins and leukotrienes), and compounds such as drugs, food additives, or industrial byproducts that enter the body through food sources, injection, inhalation from the air, or absorption through the skin. Drug biotransformation by cytochrome P-450 enzymes is one of the most important systems for drug metabolism. This system can be altered by a number of mechanisms, such as induction and inhibition, and can vary significantly among individuals. P450's are proteins of 400 to 530 aminoacids. Based on sequence similarities, P450's have been classified into about forty different families. The cytochrome P450 system has far reaching effects in medicine. It is involved in: (a) inactivation or activation of therapeutic agents, (b) conversion of chemicals to highly reactive molecules, which may produce unwanted cellular damage, cell death, or mutations, (c) participation in several steps in steroid hormone biosynthesis, and (d) metabolism of fatty acids and their derivatives.
Açıklama
[Journal of Turgut Özal Medical Center 1996;3(3):257-275]
Anahtar Kelimeler
Sitokrom P-450, Enzim, Demir-sülfür proteinleri, Biyotransformasyon, Detoksifikasyon, Cytochrome P-450, Enzyme, İron-sulphur proteins, Biotransformation, Detoxification
Kaynak
Turgut Özal Tıp Merkezi Dergisi
WoS Q Değeri
Scopus Q Değeri
Cilt
3
Sayı
3
Künye
Özerol, E.,(1996). Sitokrom p450 monooksijenaz enzim sistemleri.Turgut Özal Tıp Merkezi Dergisi, 3 (3).237-275 ss.
