Probing the renin active site by collisional quenching of endogenous fluorescence.
نویسندگان
چکیده
The structural and enzymatic aspects of renin are of great interest in hypertension research. In this paper, we examine the solution accessibility of the three tryptophan (Trp) residues of mouse submaxillary gland renin by solute collisional fluorescence quenching. Our studies indicate that there are two "classes" of Trp residues in renin: class I, a class of Trp residues which are at or near the surface of renin and fully accessible to the fluorescence quencher iodide; and class II, a class of Trp residues which are, for practical experimental conditions, totally inaccessible to the aqueous solution. The former class contains 2 Trp residues, while only a single Trp is identified in the latter class. The presence of a tetradecapeptide substrate or a nonhydrolyzable substrate analogue (peptide H-77) lowers the accessibility of iodide to the class I Trp residues. These data indicate that the class I Trp residues are at or near the peptide-binding site of renin. In addition, the finding that the class I Trp residues are quantitatively quenched more efficiently than the Trp model compound indole suggests that the environment of the class I tryptophans may be positively charged, and thus have a higher "local" concentration of iodide. These data, taken together with the available sequence and computer-generated three-dimensional structure of renin, permit us to speculate that the class I Trp residues are Trp-39 and Trp-300. This solution study of renin structure is discussed in light of the known information about renin catalysis and physiology.
منابع مشابه
The fluorescence Quenching Study of Quinine in Presence of Some Anions
The quenching of quinine fluorescence intensity in the presence of some anions in aqueous solution at ambient temperature has been investigated. The quenching is found to be collisional or dynamical in nature. This study reveals the order of two groups of quencher: NaI > NaBr > NaCl > NaF and K2Cr2O7 > KMnO4 >Na2SO4 > NaClO3. Increasing anion size in the both groups leads to an increase in the...
متن کاملProbing the Binding of Valacyclovir Hydrochloride to the Human Serum Albumin
UV-visible and Fluorescence spectroscopic methods were employed to study the interaction of human serum albumin (HSA) with Valacyclovir Hydrochloride. Additionally, molecular dynamics and molecular docking simulations were used to visualize and specify the binding site of Valacyclovir Hydrochloride. The Stern-Volmer and van't Hoff equations along with spectroscopic observations, were used to de...
متن کاملPicosecond-Resolved Fluorescence Studies of Substrate and Cofactor-Binding Domain Mutants in a Thermophilic Alcohol Dehydrogenase Uncover an Extended Network of Communication
Time-resolved fluorescence dynamics are investigated in two mutants of a thermophilic alcohol dehydrogenase (ht-ADH): Y25A (at the dimer interface) and V260A (at the cofactor-binding domain). These residues, ca. 32 Å apart, are shown to exhibit opposing low-temperature effects on the hydride tunneling step. Using single-tryptophan constructs at the active site (Trp87) and a remote, surface-expo...
متن کاملPicosecond-Resolved Fluorescent Probes at Functionally Distinct Tryptophans within a Thermophilic Alcohol Dehydrogenase: Relationship of Temperature-Dependent Changes in Fluorescence to Catalysis
Two single-tryptophan variants were generated in a thermophilic alcohol dehydrogenase with the goal of correlating temperature-dependent changes in local fluorescence with the previously demonstrated catalytic break at ca. 30 °C (Kohen et al., Nature 1999, 399, 496). One tryptophan variant, W87in, resides at the active site within van der Waals contact of bound alcohol substrate; the other vari...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of biological chemistry
دوره 260 28 شماره
صفحات -
تاریخ انتشار 1985