In:
Zeitschrift für Naturforschung B, Walter de Gruyter GmbH, Vol. 24, No. 5 ( 1969-5-1), p. 613-617
Abstract:
Thermal denaturation of RNA free coat proteins of tobacco mosaic virus (TMV) was studied for wildtype TMV (vulgare) and the temperature-sensitive mutant, Ni 118. The ability to form soluble aggregates as well as the optical properties (ORD, UV-difference spectra), and the sedimentation behavior were used as criteria for the native state. At pH 7.5, I= 0.02 denaturation is reversible for both proteins. The ORD data indicate that the denatured proteins contain residual secondary structure. The “melting temperatures”, as defined by ORD measurements (cp = 0.02 mM), are 39.5 ± 1°C for vulgare and 27 ± 1°C for Ni 118 at pH 7.5, I= 0.02. By means of the aggregation test (cp = 0.05 mM) somewhat lower melting temperatures were found under the same solvent conditions. The difference between the primary structures of vulgare and Ni 118 proteins being a proline → leucine (pos. 20) replacement, the results suggest the cyclic structure of proline (20) to have a specific stabilizing function in the three dimensional protein structure. This conclusion is supported by preliminary experiments on a temperature-sensitive mutant with a threonine residue in pos. 20.
Type of Medium:
Online Resource
ISSN:
1865-7117
,
0932-0776
DOI:
10.1515/znb-1969-0527
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
1969
detail.hit.zdb_id:
2078109-X
detail.hit.zdb_id:
124635-5
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