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W L Mattice

Publications and source records attributed to W L Mattice.

At least 37 records · Page 2Linked to original sources
PubMed1976

Conformational properties of the complexes formed by proteins and sodium dodecyl sulfate.

Circular dichroism spectra have been obtained for albumin, alpha-chymotrypsinogen, collagen, concanavalin A, elastase, hemoglobin, histone f2b, alpha-lactalbumin, lactate dehydrogenase, beta-lactoglobulin, lysozyme, myoglobin, papain, ribonuclease A, and thermolysin in the presence of sodium dodecyl sulfate and dithiothreitol. While all spectra have the shape anticipated for a mixture of random coil and alpha helix, the intensities differ markedly ([theta]222 ranges from --1400 to --15 000 deg cm2/dmol). The variation in the circular dichroism can be quantitatively explained by a model which assumes that the arginyl, histidyl, and lysyl residues have an enhanced probability of propagating a helical segment in the presence of the detergent. The model also permits the computation of dimensional properties (unperturbed end-to-end distance and radius of gyration) for polypeptides of known amino acid sequence. Such computations have been performed for 67 proteins. The computed dimensions are compatible with experimental values and with the molecular weight dependence of the transport properties of the complexes. Furthermore, the model can account for the abnormal transport properties of the sodium dodecyl sulfate complexes formed by ribonuclease A, collagen fragments, and histones f2a1, f2a2, f2b, and f3. Even though some of the protein--sodium dodecyl sulfate complexes have helical contents as high as 50%, their overall conformation more closely approximates that of a random coil than a rod.

Amino Acids↗
PubMedDate not supplied

Hydrodynamic properties and unperturbed dimensions of poly(gamma-hydroxy-L-proline) in aqueous solution.

Intrinsic viscosities and sedimentation coefficients have been measured as a function of molecular weight for poly(gamma-hydroxy-L-proline) in water. The molecular weight range covered is 9,000-35,000. High molecular weight poly(gamma-hydroxy-L-proline) in water has the hydrodynamic behavior of a random coil immersed in a good solvent, as judged by d ln [eta]/d ln M, d ln so/d ln M, dbeta/dM, and the size of beta[= nu rho (-1)]/1/3etaM-2/3(1 - nurho)-1]. The characteristic ratio, ((r2)o/nplp2) infinity, is found to be 15.9 +/- 1.6, which is not significantly different from the result of 13.7 +/- 0.9 obtained for poly(L-proline) by Mattice and Mandelkern under the same conditions. This observation casts doubt on the importance of intrachain hydrogen bonded bridges from the hydroxyl group to a carbonyl oxygen via a water molecule. The characteristic ratios and the effects of calcium chloride on the hydroynamic properties suggest that poly(L-proline) and poly(gamma-hydroxy-L-proline) possess a similar source of flexibility which is often overlooked. Two possibilities for this flexibility are a second energy minimum about the Calpha-C' bond and cis-trans isomerization about the peptide bond.

Hydrogen Bonding↗