کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10770699 1050835 2005 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Carboxy-monopeptidase substrate specificity of human cathepsin X
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Carboxy-monopeptidase substrate specificity of human cathepsin X
چکیده انگلیسی
Cathepsin X is a papain-like cysteine protease with restricted positional specificity, acting primarily as a carboxy-monopeptidase. We mapped the specificities at the S2, S1, and S1′ subsites of human cathepsin X by systematically and independently substituting the P2, P1, and P1′ positions of the carboxy-monopeptidase substrate Abz-FRF(4NO2) with natural amino acids. Human cathepsin X has broad S2, S1, and S1′ specificities within two orders of magnitude in kcat/KM, excluding proline that is not tolerated at these subsites. Glycine is not favored in S2, but is among the preferred residues in S1 and S1′, which highlights S2 as the affinity-determinant subsite. The presence of peculiar residues at several binding site positions (Asp76, His234, Asn75, and Glu72) does not translate into a markedly different sequence specificity profile relative to other human cathepsins. These findings suggest that a specific function of human cathepsin X is unlikely to result from sequence specificity, but rather from a combination of its unique positional specificity and the co-localization of enzyme and substrate in a specific cellular environment.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Biochemical and Biophysical Research Communications - Volume 329, Issue 2, 8 April 2005, Pages 445-452
نویسندگان
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