A differential scanning calorimetric study of the thermal unfolding of mutant forms of phage T4 lysozyme.


Abstract

In continuation of our earlier work on the effects of amino acid replacements on the thermodynamics of the thermal unfolding of T4 lysozyme [Kitamura, S., & Sturtevant, J. M. (1989) Biochemistry 28, 3788-3792; Connelly, P., Ghosaini, L., Hu, C.-Q., Kitamura, S., Tanaka, A., & Sturtevant, J. M. (1991) Biochemistry 30, 1887-1891; Hu, C.-Q., Kitamura, S., Tanaka, A., & Sturtevant, J. M. (1992) Biochemistry 31, 1643-1647], we report here a study by differential scanning calorimetry of the effects of five replacements at Ile3. Four of these replacements, those with Glu, Phe, Pro, and Thr, caused apparent destabilizations, while the replacement by Leu led to a small apparent stabilization. The largest observed destabilization (Ile3Pro) amounted to -3.0 kcal mol-1 in free energy at pH 2.00 and 38.8 degrees C (the denaturational temperature of the wild-type protein at this pH), and the largest stabilization amounted to +1.2 kcal mol-1 at pH 3.00 and 53.6 degrees C. Study holds ProTherm entries: 1381, 1382, 1383, 1384, 1385, 1386, 1387, 1388, 1389, 1390, 1391, 1392, 1393, 1394, 1395, 1396, 1397, 1398, 13713, 13714, 13715, 13716, 13717, 13718, 13719, 13720, 13721, 13722, 13723, 13724, 13725, 13726, 13727 Extra Details: T4 lysozyme; thermal unfolding; isoleucine; free energy;,differential scanning calorimetry

Submission Details

ID: SnLE63JB4

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:17 p.m.

Version: 1

Publication Details
Ladbury JE;Hu CQ;Sturtevant JM,Biochemistry (1992) A differential scanning calorimetric study of the thermal unfolding of mutant forms of phage T4 lysozyme. PMID:1420185
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