F Cramer’s research while affiliated with Max Planck Institute of Experimental Medicine and other places

... Despite the extensive systematic studies of various phenyl esters principally by Cramer et al., (1967), Bender et al. (Bender et al., 1966;Bender et al., 1966;VanEtten et al., 1967a;VanEtten et al., 1967b), and Breslow et al. (Breslow, 1978), hydrolysis efficacies were far from the enzymes and soon raised potential improvements by targeted CD derivatizations. ...

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Cyclodextrin based artificial enzymes

... The detailed functional elucidation of these molecules, however, had to await further studies. Their crystallization proved to be a major prerequisite for moving forward in this direction (see Refs. [234,235] among others). ...

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A History of Protein Biosynthesis and Ribosome Research

... Results in this field obtained recently e.g. by pulsed nano second fluorom etry [2] and laser light scattering [3] have caused us to use diffuse X-ray scattering tech niques as a tool to obtain m ore inform ation on the nature of these conform ational changes. Small-angle X-ray scattering is a useful technique for studying the conform ation o f biopolym ers in solution, and a num ber of studies has been carried out on tRNAs already [4][5][6][7][8]. U nfortunately aggregation o f the tRNAs, the degree of which seems to vary with the solution conditions, may falsify determ inations of param eters describing the large dimensions o f the * D edicated to Prof. O. Kratky on the occasion of his 80th birthday. ...

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Small- and Large-Angle X-Ray Scattering Studies of Counter Ion Influence on tRNA Conformation*

... Recently, tRNA's modified in the 3'-terminal adenosine or in the penultimate cytidine nucleotides have been investigated; some of these tRNA's can be aminoacylated. One of these can be prepared by oxidizing the 3'-terminal ribose with periodate and reduction of the dialdehyde with sodium borhydride to tRNA-C-C-A,,,,, [7]. Other derivatives can be prepared by incorporating ATP analogues to tRNA-C-C or CTP analogues and ATP to tRNA-C with the tRNAnucleotidyl transferase. ...

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The specificity of peptidyl-tRNA hydrolase from E. coli

... Negative electric-field catalysis was only detectable below I = À 4.5 A [73][74][75] (Figures 2c, S29). According to gas chromatography (GC) analyses compared to internal standards (Figures S12-S27 , Table S1), [53] total conversion (P + O) after one passage through the microfluidic reactor increased with the external field up to η = 70 % at I = À 5.0 A. Most main products were identified and quantified by comparing their GC traces with those of commercial samples, and their sum afforded yields P (Figures 2c, red; S3, S29, Table S2). Small peaks and missing matter, lost by evaporation, etc, were summarized as others (O, Figure 2c, teal). ...

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Electric‐Field Catalysis on Carbon Nanotubes in Electromicrofluidic Reactors: Monoterpene Cyclizations

... The wyebutine base would be more exposed to the solvent and have a shorter fluorescence lifetime as a result. However, both NMR data (205,206) and chemical modification studies (207) are inconsistent with a 5ś tack. For the moment, this matter is unresolved. ...

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Fluorescence Studies of Nucleic Acids: Dynamics, Rigidities, and Structures

... As regards use of inorganic oxides, silica and modified silica, alumina, zeolites, clays, and so forth have found wide applications in promoting various organic reactions in solution phase or in solvent-free conditions [31][32][33][34][35][36][37][38]. On the other hand, organic polymers such as polystyrene (PS) or that partially crosslinked with divinylbenzene (DVB) have remained the major choice besides uses of some other dendrimers [39][40][41][42][43][44][45][46][47][48][49][50]. The choice of solid phase, polymers with suitable linkers, the nature of binding with the substrate/reagent (covalent or noncovalent), stability, and recyclability have remained some of the salient points for successful and efficient solid-phase synthetic protocol. ...

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ChemInform Abstract: Solid-Phase Organic Synthesis and Catalysis: Some Recent Strategies Using Alumina, Silica, and Polyionic Resins

... In all other tRNAs of known sequence (e.g., in tRNAAlS from yeast, whose base sequence is shown in Fig. la (89). Many attempts to determine the secondary (85,275) and tertiary (202) structure of tRNA have been 269 VOL. 33X -1969 made (114), so far providing no really convincing evidence for any model. ...

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Mechanism of protein biosynthesis

... Likewise, activity of human mt-TyrRS-DS4 (as well as full-length TyrRS) requires reducing conditions, indicating the necessity of nonoxidized cysteine residues for crystallization and functionality. Cysteine residues were proposed to participate in the catalytic mechanism of yeast TyrRS, based on the observation that modification of two reactive sulfhydryl groups per subunit leads to inactivation of the enzyme (Faulhammer and Cramer, 1977). Given the location of the cysteine residues in the structure of human mt-TyrRS (Figure 2), the role of these residues cannot be directly correlated with the catalytic mechanism of tyrosylation. ...

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Cristallogenesis and structural studies applied to aminoacyl-tRNA synthetase

... EF-Tu also acts as an isomerase, utilizing a mixture of the 2′(3′)-aminoacyl tRNA isomers as a substrate, and converting them to uniform 3′-complexes [11]. Both 2′-and 3′-aminoacyl isomers of 'deoxy' RNAs can bind EF-Tu · GTP, albeit with 50fold lower efficiency as compared to the native 2′(3′)aminoacyl-tRNA [23,24]. The preference for the 3′-isomer of aa-tRNAs, upon complex formation with EF-Tu, was also demonstrated by NMR results published by S. Yokoyama et al. [25], and supported more recently by X-ray analysis of EF-Tu complexed with aa-tRNA [26], and data from steady-state and transient kinetic experiments [26,27]. ...

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The mechanistic and evolutionary aspects of the 2′- and 3′-OH paradigm in biosynthetic machinery