The kinetic properties of arginase in sperm cells of inferile men
AbstractNowadays the role of NO in the development of male infertility is actively studied. Arginase (EC 126.96.36.199) is a manganese metalloenzyme which converts L-arginine to L-ornithine and urea and reciprocally regulates NO production. Although arginase activity has usually been detected in the reproductive tract, including spermatozoa, no data relating to the kinetic properties of the enzyme in ejaculated spermatozoa has been reported. This study was designed to study the kinetic parameters of arginase of spermatozoa of infertile men. Spermatozoa arginase activity was measured by determining levels of urea production. Kinetic analysis of the enzyme reaction was performed in a standard incubation system with modified physical and chemical characteristics or the respective components (the substrate concentration, Mn2+ concentration, incubation time and protein content). Pathobiochemical and kinetic properties of sperm arginase obtained from human normozoo- and pathospermic samples were compared. The maximum rate of L-arginine hydrolysis (detrermined by L-arginine) for arginase of spermatozoa obtained from men with preserved fertility was 2.0, 1.8 and 1.9 times greater than this value for oligo-, astheno- and oligoasthenozoospermic samples respectively. However, affinity constants for L-arginine was not significantly different between fertile and infertile men. The maximum rate of L-arginine hydrolysis (deretmined by Mn2+) for arginase of spermatozoa obtained from men with preserved fertility was 1.6, 1.7 and 1.7 times greater than this value for oligo-, astheno- and oligoasthenozoospermic samples respectively. However, affinity constants for Mn2+ were not significantly different between fertile and infertile men. In the whole range of time, the urea production by arginase in sperm cells obtained from oligozoospermic samples is much lower compared to value in healthy donors. The results of kinetic analysis indicate that urea production by arginase is much more intense in the control group than in patients with various forms of pathospermia. The initial (instantaneous) reaction rate of arginase reaction was lower for oligozoospermic samples compared to normozoospermic samples. It has been found that inhibition of arginase activity in sperm cells of infertile men occurs by non-competitive type and was related to marked decrease in maximum reaction rate while affinity of arginase to L-arginine and Mn2+ was unaffected.
Atig, F., Raffa, M., Habib, B. A., Kerkeni, A., Saad, A., & Ajina, M. (2012). Impact of seminal trace element and glutathione levels on semen quality of Tunisian infertile men. BioMed Central Urology, 12, 6.
Balercia, G., Moretti, S., Vignini, A., Magagnini, M., Mantero, F., Boscaro, M., Ricciardo-Lamonica, G., & Mazzanti, L. (2004). Role of nitric oxide concentrations on human sperm motility. Journal of Andrology, 25(2), 245–249.
Dillon, B. J., Holtsberg, F. W., Ensor, C. M., Bomalaski, J. S., & Clark, M. A. (2002). Biochemical characterization of the arginine degrading enzymes arginase and arginine deiminase and their effect on nitric oxide production. The Medical Science Monitor, 8(7), BR248–253.
Eskiocak, S., Gozen, A. S., Taskiran, A., Kilic, A. S., Eskiocak, M., Gulen, S. (2006). Effect of psychological stress on the L-arginine-nitric oxide pathway and semen quality. Brazilian Journal of Medical and Biological Research, 39(5), 581–588.
Fafula, R. V., Iefremova, U. P., Onufrovych, O. K., Maksymyuk, H. V., Besedina, A. S., Nakonechnyi, I. A., Vorobets, D. Z., & Vorobets, Z. D. (2018). Alterations in arginase-NO-synthase system of spermatozoa in human subjects with different fertility potential. Journal of Medical Biochemistry, 37, 1–7.
Fafula, R. V., Onufrovych, O. K., Iefremova, U. P., Vorobets, D. Z., & Vorobets, Z. D. (2016). Osoblyvosti arginaznogo shlyahu metabolismu L-argininu v spermatozoidach cholovikiv pry riznyh formach patospermiji [The peculiarrities of arginase pathway of L-arginine in spermatozoa in men with different forms of pathospermia]. Fiziologichnyj Zhurnal, 62(5), 83–90 (in Ukrainian).
Hadwan, M. H., Almashhedy, L. A., & Razzaq, A. S. (2014). Study of the effects of oral zinc supplementation on peroxynitrite levels, arginase activity and NO synthase activity in seminal plasma of Iraqi asthenospermic patients. Reproductive Biology and Endocrinology, 12, 1.
Kosterin, S. A., & Burchinskaya, N. F. (1987). Metod opredileniya kineticheskih characteristic Ca2+-transportnyh sistem v subkletochnyh structurah gladkih myshc [Method for determination of kinetic parameters of Ca2+-transporting systems of subcellular structures of smooth muscle]. Ukrainian Biochemical Journal, 59(2), 66–69 (in Russian).
Lowry, O. H., Rosebrough, N. J., Farr, A. L. (1951). Protein measurement with the Folin phenolreagent. The Journal of Biological Chemistry, 193, 265–275.
Luk, B. H., & Loke, A. Y. (2015). A review of supportive interventions targeting individuals or couples undergoing infertility treatment: Directions for the development of interventions. The Journal of Sex and Marital Therapy, 10, 1–19.
Mori, M. (2007). Regulation of nitric oxide synthesis and apoptosis by arginase and arginine recycling. The Journal of Nutrition, 137, 1616–1620.
Porro, B., Eligini, S., Squellerio, I., Tremoli, E., & Cavalca, V. (2014). The red blood cell: A new key player in cardiovascular homoeostasis? Focus on the nitric oxide pathway. Biochemical Society Transactions, 42(4), 996–1000.
Racke, K., & Warnken, M. (2010). L-arginine metabolic pathways. The Open Nitric Oxide Journal, 2, 9–19.
Shen, L. J., Beloussow, K., & Shen, W. C. (2005). Accessibility of endothelial and inducible nitric oxide synthase to the intracellular citrulline–arginine regeneration pathway. Biochemical Pharmacology, 69, 97–104.
Topal, G., Brunet, A., Walch, L., Boucher, J. L., & David-Dufilho, M. (2006) Mitochondrial arginase II modulates nitric-oxide synthesis through nonfreely exchangeable L-arginine pools in human endothelial cells. The Journal of Pharmacology and Experimental Therapeutics, 318, 1368–1374.
Venkatakrishnan, P., Nakayasu, E. S., Almeida, I. C., & Miller, R. (2010). Arginase activity in mitochondria – An interfering factor in nitric oxide synthase activity assays. Biochemical and Biophysical Research Communications, 394(3), 448–452.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons «Attribution» 4.0 License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.