Uğur AŞKIN, Fikret KARATAŞ, Yusuf TÜRKÖZ, Süleyman AYDIN

Paraoksonaz-1 Enziminin Bazı Kinetik Özelliklerinin İncelenmesi ve Ghrelin Hormonu ile İlişkisi

Bu çalışmada, sığır karaciğerinden saflaştırılan ve metabolizma için büyük öneme sahip olan Paraoksonaz-1 E.C. 3.1.1.2. ve E.C. 3.1.8.1. enziminin bazı kinetik özellikleri ile ghrelin hormonu arasındaki ilişki araştırıldı. Paraoksonaz-1 enziminin pH:7.1 ve 37 ºC’de optimum aktivite gösterdiği saptandı. Substrat olarak fenil asetat kullanıldığında Km değeri 0.074 + 0.002 mM ve Vmax değeri 36.42 U/mg olarak hesaplandı. Paraoksonaz-1 enziminin aktif ghrelin hormonuna etki ettiği ve aktif ghrelin hormonunu 20 dakika sonunda % 9.5 oranında inaktif ghreline dönüştürdüğü tespit edildi

Anahtar Kelimeler:

Paraoksonaz-1, Kinetik özellikler, Ghrelin, HPLC

Investigation of the Some Kinetic Features of Paraoxonase-1 Enzyme and Its Relationship with Ghreline Hormone

In this study, some of the kinetic features of paraoxonase-1 E.C. 3.1.1.2. and E.C. 3.1.8.1. that is purified from bovine liver and has major importance for metabolism and, the relationship between paraoxonase-1 and ghrelin hormone has been investigated. It is seen that paraoxonase-1 displays optimum activity at pH: 7. 1 and 37 ºC. When phenyl acetate is used as a substrate, it is calculated that Km value was 0.074 + 0.002 mM and Vmax value was 36.42 U/mg. It is determined that paraoxonase-1 interacts with the active ghrelin and converts it into the inactive ghreline at the end of 20 minutes. The converting rate was found as 9.5 %

Keywords:

Paraoxonase-I, Kinetic features, Ghrelin, HPLC.,

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Primo-Parmo SL, Sorenson RC, Teiber J, La Du BN. The aryesterase gene (PON1) is one member of a multigene family. Genomics 1996; 33: 498-509.
Mackness MI, Mackness B, Durrington PN, Connelly PW, Hegele RA. Paraoxonase: biochemistry, genetics and relationship to plasma lipoproteins. Curr Opin Lipidol 1996; 7: 69-76.
Erden İ. ST Elevasyonlu Miyokard İnfarktüslü (stemi) Hastalarda polimorfizmi. Uzmanlık Tezi, 2004. Geni met-leu/55
Deakin SP, James RW. Genetic and environmental modulating serum concentrations and activities of the antioxidant enzyme paraoxonase-1. Clin Sci 2004; 107: 435-47.
La Du BN, Aviram M, Billecke S, Navab M. On the physical role(s) of the paraoxonases. Chem Biol Inter 1999; 120: 379-88.
Heijmans BT, Westendorp RGJ, Lagaay AM, Knook DL, Kluft C, Slagboom PE. Common paraoxonase gene variants, mortality risk and fatal cardiovascular events in elderly subjects. Atherosclerosis 2000; 149: 91-7.
Hasselwander O, McMaster D, Fogarty AD, Maxwell AP, Nicholls DP, Young JS. Serum paraoxonase and platelet-activating factor acetylhydrolase in chronic renal, failure. Clin Chem 1998; 44: 179-182.
Kelso GJ, Stuart WD, Richter RJ, Furlong CE, Jordon TJ, Harmony JAK. Apolipoprotein J is associated with paraoxonase in human plasma. Biochemistry 1994; 33: 832-9.
Eckerson HW, Romson J, Wyte C, La Du BN. The human identification of phenotypes by their response to salts. Am J Hum Genet 1983; 35: 214-27.
Gan N, Smolen A, Eckerson W, La Du BN. Purification of human serum paraoxonase/arylesterase. Evidence for one esterase catalyzing both activities. Drug Metab Dispos 1991; 19: 100-6.
Öztürk H. Diabetes mellitus’da paraoksonaz aktivitesi ve AOPP düzeyleri. Tıbbi Biyokimya Uzmanlık Tezi. 2008.
Mackness MI, Arrol S, Durington PN. Paraoxonase prevents accumulation of lipoperoxides in low density lipoprotein. FEBS Lett 1991; 286: 152-4.
Rousselot DB, Therond P, Beaudeux JL, Peynet J, Legrand A, Delatre J. High density lipoproteins and the oxidative hypothesis of atherosclerosis. Clin Chem Lab Med 1999; 37: 939-49.
Aviram M, Rosenblot M, Bisgaier CL, Newton RS, Primo Parmo SL, La Du BN. Paraoxonase inhibits high density lipoprotein oxidation and preserves its functions. J Clin Invest 1998; 101: 1581-90.
Kojima M, Hosoda H, Date Y, Nakazato M, Matsuo H, Kangawa K. Ghrelin is a growth hormone-realising acylated peptide from stomach. Nature 1999; 402; 656-9.
Aydin S, Özkan Y, Caylak E. Ghrelin and its biochemical functions. Turkiye Klinikleri J Med Sci 2006; 26: 272-83.
Aydin S. Ghrelin Hormonunun Keşfi: Araştırmaları ve Klinik Uygulamaları. Türk Biyokimya Dergisi 2007; 32: 76-89.
Ariyasu H, Takaya K, Tagami T, et al. Stomach is a major source of circulating ghrelin and feeding state determines plasma ghrelin-like immuno reactivity levels in humans. J Clin Endocrinol Metab 2001; 86: 4753-8.
Kaiya H, Darras VM, Kangawa K. Ghrelin in birds: Its structure, distribution and function. J Poul Sci 2007; 44: 1-18.
Beaumont NJ, Skinner VO, Tan TM, et al. Ghrelin can bindto a species of high density lipoprotein associated with paraoxonase. J Biol Chem 2003; 278: 8877-80.
Korbonits M, Kojima M, Kangawa K, Grossman AB. Presence of ghrelin in normal and adenomatous human pituitary. Endocrine 2001; 14: 101-4.
Gualillo O, Caminos J, Blanco M, et al. Ghrelin, a novel placental-derived hormone. Endocrinology 2001; 142: 788-94.
Korbonits M, Bustin SA, Kojima M. The expression of the growth hormone secretagogue receptor ligand ghrelin in normal and abnormal human pitiutary and other neuroendocrine tumors. J Clin Endocrinol Metab 2001; 86: 881-7.
Casanueva FF, Dieguez C. Ghrelin; the link connecting growth with metabolism and energy homeostasis. Rev Endocrine Dis 2002; 3: 325-38.
De Ambrogi M, Volpe S, Tamanini C. Ghrelin: central and peripheral effects of a novel peptydil hormone. Med Sci Monit 2003; 9: 217-24.
Schwartz MW, Woods SC, Porte D, et al. Central nervous system control of food intake. Nature 2000; 404: 661-71.
Janeckova R. The role of leptin in human physiology and pathophysiology. Physiol Res 2001; 50: 443-59.
Tschöp M, Smiley D, Heiman ML. Ghrelin induces adiposity in rodents. Nature 2001; 407: 908-13.
Soriano-Guillen L, Barrios V, Chowen J, et al. Ghrelin levels from fetal life through early adulthood: relationship with endocrine and metabolic and anthropometric measures. J Pediatr 2004; 144: 30-5.
Eckerson H, Wyte C, La Du B. The human serum paraoxonase/arylesterase polymorphism. Am J Hum Genet 1983; 35: 1126-38.
Karataş F, Aydın S, Geçkil H. Ghrelin hormonunun HPLC ile belirlenmesi. 21. Ulusal Kimya Kongresi, 2006, Malatya.
Sinan S, Koçkar F, Arslan O. Novel purification strategy for human PON1 and inhibition of the activity by antibiotics. Biochimie 2006; 88: 565-74.
aminoglikozide derived
Golmanesh L, Mehrani H, Tabie M. Simple procedures for purification and stabilization of human serum paraoxonase-1. J Biochem Biophys Methods 2008; 70: 1037-42.
Rodrigo L, Gil F, Hernandez AF, Marina A, Vazquez J, Pla A. Purification and characterization of paraoxon hydrolase from rat liver. Great Britain Biochem J 1997; 321: 595- 601.