الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Cystathionine γ-Lyase (CGL, E.C. 4.4.1.1) is a pyridoxal phosphate dependent enzyme catalyzes the γ-elimination of cystathionine to cysteine, α-ketobutyrate and ammonia (Nagasawa et al., 1984; Smacchi and Gobbetti, 1998). CGL is a key enzyme in transsulfuration pathways, transformation of homocysteine to cysteine as a part of L-methionine cycle, in addition to, methionine γ-lyase, cystathionine β-lyase (CBL), cystathionine β-synthase and cystathionine γ-synthase. However, cystathionine β-lyase (E.C. 4.4.1.8) catalyzes the α- and β- cleavage of L-cystathionine to pyruvate, L-homocysteine and ammonia (Kase and Nakayama, 1974; Uren, 1987; Dias and Weimer, 1998). Thus, CGL and CBL are the two pyridoxal-5-phosphate dependent enzymes which mainly cleavage the cystathionine, via transsulfuration and reverse transsulfuration pathways, respectively (Mehta and Christen, 2000; Irmler et al., 2008). Cystathionine γ-lyase has received much attention for its therapeutic applications against cystathioninuria and cardiovascular diseases related to hyper-accumulation of cystathionine (Stabler et al., 1993; Kraus et al., 2009). Biochemically, cystathioninuriarefers to a hyper-accumulation of cystathionine due to the malfunctions of CGL and CBL or deficiency of their co-enzymes pyridoxal phosphate (Bittles and Carson, 1974; Wang and Hegel, 2003). Cystathioninuria, is a benign of biochemical anomaly associated with wide range of diseases as developmental delay (Harris et al., 1959), thrombocytopenia (Mongeau et al., 1967), diabetes (Perry et al., 1967), cystic fibrosis, celiac disease (Endres and Wuttge, 1978) and vast array of diseases as reviewed by Wang and Hegele (2003). CGL was frequently purified, biochemically and molecularly characterized from various bacterial isolates in contrary to the scarce publication of the enzyme from fungi. However, the enzymes from eukaryotes display affordable biochemical and pharmacokinetic properties, than the corresponding enzyme from prokaryotes as reviewed by El-Sayed (2010).