Effects of Mutations

Colquhoun D (1998) Binding, gating, affinity and efficacy the interpretation of structure-activity relationships for agonists and of the effects of mutating receptors. BrJ Pharmacol 125 924—947... 

An additional sequence element within the mouse ZP3 promoter has been identified as the binding site of an oocyte-specific protein called OSP-1 (Schickler et al., 1992), although the possible effect of mutations of this element on transcriptional activity has not been established. Nonetheless, it is interesting that a similar sequence (GATGA) is present 40 nucleotides upstream of the c-mos transcription initiation site (Fig. 5), although deletion of this element had no discernible effect on the activity of the c-mos promoter in microinjected oocytes (Pal et al., 1991). 

Table 7.4 Effects of mutations of Thr40 and His45 on the kinetic parameters for tyrosyl-tRNA synthetase...

The effect of mutation is different in case of stopped samples, but the phenomenon cannot be completely avoided. Here, the experimental time period At is determined by the poison diffusion. The catalyst poison solution is sprayed on top of a reacting sample and then diffuses into the core of the sample where it stops the reaction sequentially layer by layer. This leads to small inhomogeneity in the sample, since the reaction near the upper surface is stopped earlier than the reaction near the bottom of the mold. 

Engel, J. and Prockop, D.J. (1991) The zipper-like folding of collagen triple helices and the effects of mutations that disrupt the zipper. Annual Review of Biophysics and Biophysical Chemistry 20, 137—152. 

Dehdashti, S.J., Doan, C. N., Chao, K. L., and Yoder, M. D. (2003). Effect of mutations in the T1.5 loop of pectate lyase A from Erwinia chrysanthemi EC16. Acta Crystallogr. D Biol. Crystallogr. 59, 1339—1342. 

In addition to the effect of mutations at Phe-82 on the stability of the cytochrome c active site, the intense, negative Soret Cotton effect in the circular dichroism spectrum of ferricytochrome c is profoundly affected by the presence of non-aromatic amino acid residues at this position [115]. Recent examination of six position-82 iso-l-ferricytochrome c mutants establishes that while Tyr-82 exhibits a Soret CD spectrum closely similar to that of the wild-type protein, the intensity of the negative Soret Cotton affect varies with the identity of the residue at this position in the order Phe > Tyr > Gly > Ser = Ala > Leu > He, though the Ser, Ala, He, and Leu variants have effectively no negative Soret Cotton effect [108]. 

Effect of mutations in H2 signalling (HupRiHupTUV) or redox signalling (RegA/RegB) pathways on hydrogenase activity in R. capsulates... 

Brock BJ, Waterman MR. 2000. The use of random chimeragenesis to study structure/function properties of rat and human P450cl7. Arch Biochem Biophys 373(2) 401 Colquhoun D. 1998. Binding, gating, affinity and efficacy the interpretation of structure-activity relationships for agonists and of the effects of mutating receptors. Br J Pharmacol 125(5) 924. 

Fig. 6.4 In vitro effects of mutation on desensitization and internalization of the dopamine receptor. Shown here are effects of mutation on dose-dependent intracellular cyclic adenosine monophosphate (cAMP) accumulation (A and B) and binding curves (C and D) for artificial ligand (SCH 23390) using three constructs controls (wild type, A and C) and the Thr360Ala mutant (360, B and D). In the desensitization experiments, cells were preincubated with 10 oA/ dopamine (o) or vehicle ( ) for 20min, and increasing concentrations of dopamine (10 to 10 (iM) were added to assess cAMP accumulation. Note that loss of efficacy and potency seen in wild-type cells (A) disappeared with the Thr360Ala mutation (B). Conversely, internalization, assessed by decrease in SCH23390 binding (C) after pretreatment with lOpM dopamine (o, compared to vehicle ), was essentially unchanged by the Thr360Ala mutation (D)...

The effect of mutations in eRFl and eRF3 on the efficiency of translation termination in yeast has been extensively studied. A variety of mutations in both translation termination factor subunits results in a nonsense suppression phenotype (Eustice et al. 1986 Song and Liebman 1989 All-Robyn et al. 1990 Wakem and Sherman 1990 Stansfield et al. 1995a, 1997 Bertram et al. 2000 Velichutina et al. 2001 Cosson et al. 2002 Bradley et al. 2003 Chabelskaya et al. 2004 Salas-Marco and Bedwell 2004). 

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