Muzaffer ÜSTDAL, Recep SARAYMEN, Eser KILIÇ

Determination of effects and binding properties of N-nitrosomorpholine and N-nitrosopyrrolydine on human acrosin by thin layer chromatography

Amaç: Akrozin kendine özgü, tripsin benzeri bir akrozomal proteinaz olup, memeli fertilizasyonunda gereklidir. Nitrozaminler oldukça geniş bir kimyasal bileşik grubudur ve test edildiği bütün hayvan grublarında kansere sebebiyet verdiği gösterilmiştir ve insanlar üzerinde de aynı etkiye sahip olabileceği konusunda düşünceler vardır. Çalışmanın amacı, nitrozamin’in in virto etkisinin insan akrozin aktivitesi ve bazı amino asitler (triptofan, fenilalanin, histidin, tirozin, prolin, sistin, metionin ve arjinin) üzerine olan etkisini incelemektir. Gereç ve Yöntem: Akrozinin yapısında yer alan bu amino asitlere nitrosaminin bağlanması ince tabaka kromatografisi ile incelenmiştir. Bulgular: Çalışmada 24 saat inkübasyon sonucunda, nitrozamin aminoasitlerin üzerine olan etkisinin zamana bağlı olarak arttığı kontrol grubu olan serbest amino asid, serbest NPOR ve serbest NPYR ile karşılaştırılarak gösterilmiştir. Sonuç: Reaksiyon hızının zamana bağlı olarak arttığını ve sonucunda da oluşan ürünün zamana bağlı olarak arttığı görülmüştür, diğer bir deyişle amino asidlerin nitrozamine bağlanması zamana bağlı olarak artmaktadır. Elde edilen sonuçlar; nitrozaminlerin akrozin üzerine non-kompatatif inhibitör etkisine sahip olduğunu göstermiştir.

N-nitrosomorfolin ve N-nitrosopirolidin'in insan akrosinine bağlanma özelliğinin ve etkisinin ince tabaka kromatografisi ile belirlenmesi

Aim: Acrosin is a unique trypsin-like acrosomal proteinase that is required for mammalian fertilization. Nitrosamines are a large group of chemical compounds that have been found to be carcinogenic in all species of animals tested and thus suspected to be a human carcinogen. The purpose of the our study was to investigate the in vitro effect of nitrosamine, on human acrosin activity and some of the main amino acids (tryptophan, phenylalanine, histidine, tyrosine, pyroline, cysteine, methionine and arginine) Material and Methods: In vitro effect of nitrosamine, on human acrosin activity and some of the main amino acids, which are responsible for the constitution of acrosin, was investigated by thin layer chromatography. Results: Our results showed that nitrosamines can have non-competitive inhibitory role on enzyme activity. Results of effect of nitrosamines on some of the main amino acids showed that 24 hours incubated amino acidnitrosamine mixtures areas were smaller then free amino acid, free NMOR and free NPYr, indicating that reaction velocity was increased as in a time-dependent manner, therefore the amount of product was increased. Conclusion:It was observed that the reaction velocity increased with time and that the resulting product increased with time. In other words, binding of amino acids to nitrosamine increases in a time depended manner. The present results indicated the non-competitive inhibitory effect of nitrosamines on acrosin.

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