Protease IgA1 Ureaplasma urealyticum bukan enzim tapi logam dan zimografik

Abstract

Abstrak

              Ureaplasma urealyticum merupakan organisme komensal terkecil pada traktus urogenital manusia. Mikroba itu berperan menting dan berasosiasi dengan beragam penyakit ibu dan bayi baru lahir. Salah satu faktor penyebab terjadinya penyakit trsebut ialah protease IgA1. Protease IgA1 mampu memecah antibodi mukosa terdepan manusia, IgA1. Enzim tersebut dikelompokkan menjadi beberapa tipe berdasarkan hambatan aktivitasnya oleh berbagai senyawa inhibitor. Penelitian ini menguji inhibisi aktivitas protease IgA1 ureaplasma terhadap inhibitor protease logam, EDTA, dan inhibitor protease serin, PMSF. Ternyata EDTA dengan konsentrasi 0,1, 1,0 dan 10,0mM, dan PMSF konsentrasi 0,1, 0,5 dan 1,0 mM tidak mampu menghambat aktifitas pemecahan IgA1 oleh protein total sel uraplasma. Selanjutnya, pengukuran aktivitas proteolisis protease IgA1 dilakukan menggunakan teknik zomografi dengan substrat kasein dan kontrol positif Igase N. Gonorrhoeae. Namun hasil zomografi menggunakan SDS-PAGE untuk menguji hal di atas tiak memperlihatkan pemecahan fregmen kasein 29 kDa seperti yang diharapkan. Sehingga dapat disimpulkan protease IgA1 ureaplasma bukanlah tipe protease logam dan tidak memiliki sifat zimogram.

Kata kunci : proteaseIgA1, protease logam, protease serin, inhibitor protease, kasein, zimogram.

Abstract

              Ureaplasma urealyticum is one of the smallest inhabitants of human urogenital tract. The microbe plays important role in diseases involving mother and her newborn. One of the pathogenic factor is IgA1 protease. The enzyme cleaves human first line mucolas antibody. IgA1. Based on its inhibition, the enzyme is grouped into several categories. Weinhibited the enzyme activity using inhibitors such as EDTA and PMSF againt metallo- and serine- protease activities. Respectively. Neither EDTA at 0.1, 1.0 and 10.0 mM nor PMSF at 0,1, 0,5 and 1.0 mM was able to inhibit the IgA1 cleavage by total ureaplasma protein extract. Subsequently, using casein as enzymatic substrate and Igase purified from N. Gonorrhoeae as positive control, we tested proteolytic activity of the ureaplasma IgA1 protease. Zymography of the assay on an SDS-PAGE resulted that none of 29 kDa casein fregment was cleaved by the enzyme the result suggest that ureaplasma IgA1 protease is neither metallo- nor a zymographic- type protease

Keyword : metallo-protease, serine-protease, IgA1 protease, IgA1, Igease, protease inhibitor, casein, zymogram