Süt Alkali Proteinazı Plazmin

Plazmin, tripsin benzeri, kan kaynaklı bir alkali serin proteinazdır. Sütte az miktarda aktif olmak üzere daha çok inaktif zimojeni olan plazminojen olarak bulunur. Isıya karşı dirençli bir enzim olan plazmin β-, αs1- ve αs2-kazeinler üzerine etkilidir. Bu nedenle süt ürünlerinin lezzet ve tekstürü üzerine de etkilidir. Bu özellikleri nedeniyle araştırmalar daha çok plazminin peynir ve UHT sütteki etkileri üzerine yoğunlaşmıştır. Bu derlemede, sütteki plazmin sistemi, plazminin süt proteinlerine ve süt ürünlerinin kalitesi üzerine olan etkileri incelenmiştir. 
Anahtar Kelimeler:

Plazmin, süt, proteoliz

The Milk Alkaline Proteinase Plasmin (Turkish with English Abstract)

Plasminis a trypsin-like alkaline serine proteinase originating in the blood. Most of the enzyme in milk is present as the inactive zymogen called plasminogen whereas a little amount of enzyme is active. Plasmin which is a heat-stable enzyme has activity on β-, αs1-, and αs2-CN. Because of its properties, most of the studies have been focused on its effects on cheese and UHT milk. In this review, plasmin system in milk, effects of plasmin on milk proteins and quality of milk products were investigated.

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  • Farkye NY and Imafidon GI. 1995. Thermal denaturation of indigenous milk enzymes. In Heat induced changes in milk, P.F. Fox (eds.), (2nd ed.), pp. 331–348, Brussels, International Dairy Federation.
  • Nielsen SS. 2003. Plasmin system in milk. In Encyclopedia of Dairy Sciences. Vol II., H. Roginski, JW Fuquay, PF Fox (eds.), pp. 929–934. Academic Press, London, UK.
  • Fox PF and Kelly AL. 2006. Indigenous enzymes in milk: Overview and historical aspects–Part 1. Int Dairy J, 16, 500–516.
  • Bastian ED and Brown RJ. 1996. Plasmin in milk and dairy products: an update. Int Dairy J, 6, 435–457.
  • Sousa MJ, Ardö Y and McSweeney PLH. 2001. Advances in the study of proteolysis during cheese ripening. Int Dairy J, 11, 327–345.
  • McSweeney PLH. 2004. Biochemistry of cheese ripening. Int J Dairy Tech, 57 (2/3): 127–144.
  • Fox PF. 2002. Significance of indigenous enzymes in milk and dairy products. In Handbook of Food Enzymology, JR Whitaker, AGJ Voragen and DWS Wong (eds.), pp. 255–277, Marcel Dekker Inc., New York, USA.
  • Walstra P, Geuris TJ, Noomen A, Jellema A and van Boekel MAJS. 1999. Dairy Technology: Principles of Milk Proper- ties and Processes. Marcel Dekker Inc. 727p, New York, USA.
  • Stepaniak L. 2004. Dairy enzymology. Int J Dairy Tech, 57 (2/3), 153–171.
  • Crudden A, Fox PF and Kelly AL. 2005. Factors affecting the hydrolytic action of plasmin in milk. Int Dairy J, 15, 305–313.
  • Benfeldt C, Larsen LB, Rasmussen JT, Andersen PA, and Petersen T. 1995. Isolation and characterization of plasmi- nogen and plasmin from bovine milk. Int Dairy J, 5, 577-592.
  • Baldi A, Savoini G, Chali F, Fantuz F, Senatare E, Bertocchi L and Politis I. 1996. Changes in plasmin-plasminogen- plasminogen activator system in milk from Italian Friesian herds. Int Dairy J, 6, 1045-1053.
  • Wilkinson MG and Kilcawley KN. 2005. Mechanisms of incorporation and release of enzymes into cheese during ripe- ning. Int Dairy J, 15, 817–830.
  • Metwalli AAM, de Jongh HHJ and van Boekel MAJS. 1998. Heat inactivation of bovine plasmin. Int Dairy J, 8, 47–56.
  • Politis, I. 1996. Plasminogen activator system: Implication for mammary cell growth and involution. J Dairy Sci, 79, 1097–1107.
  • Silanikove N, Merin U and Leitner G. 2006. Physiological role of indigenous milk enzymes: An overview of an evolving picture. Int Dairy J, 16, 533–545.
  • Le Bars D and Gripon JC. 1993. Hydrolysis of αs1-casein by bovine plasmin. Lait, 73, 337–344.
  • McSweeney PLH, Olson NF, Fox PF, Healy A and Hİjrup P. 1993. Proteolytic specificity of plasmin on bovine αs1-ca- sein. Food Biotechnol 7, 143–158.
  • Doi H, Kawaguchi N, Ibuki F and Kanamori M. 1979. Susceptibility of κ-casein components to various proteases. J Nutr Sci Vitaminol 25, 33–41.
  • Crudden A, Afoufa-Bastien D, Fox PF, Brisson G and Kelly AL. 2005. Effect of hydrolysis of casein by plasmin on the heat stability of milk. Int Dairy J, 15, 1017–1025.
  • Manzi P and Pizzoferrato L. 2006. UHT thermal processing of milk. In Thermal Food Processing: New Technologies and Quality Issues, Da-Wen Sun (eds), pp. 299-334, USA, CRC Press.
  • Farkye NY and Fox PF. 1992. Contribution of plasmin to Cheddar cheese ripening: effect of added plasmin. J Dairy Res, 59 209–216.
  • Law BA. 2001. Controlled and accelerated cheese ripening: the research base for new technologies. Int Dairy J, 11, 383–398.
  • Considine T, McSweeney PLH and Kelly AL. 2002. The effect of lysosomal proteinases and plasmin on the rennet co- agulation properties of skim milk. Milchwissenschaft, 57 425–428.