THERMALLY DENATURED RIBONUCLEASE-A RETAINS SECONDARY STRUCTURE AS SHOWN BY FTIR

被引：73

作者：

SESHADRI, S ^{[1
]}

OBERG, KA ^{[1
]}

FINK, AL ^{[1
]}

机构：

[1] UNIV CALIF SANTA CRUZ,DEPT CHEM & BIOCHEM,SANTA CRUZ,CA 95064

来源：

BIOCHEMISTRY | 1994年 / 33卷 / 06期

关键词：

D O I：

10.1021/bi00172a010

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Fourier transform-infrared (FTIR) spectroscopy has been used to test for the presence of nonrandom structure in thermally denatured ribonuclease A (RNase A) at pH* 2.0 (uncorrected pH measured in D2O). The amide I Spectral region of the native and thermally denatured protein was compared. A substantial decrease in the amount of beta-sheet and alpha-helix and a corresponding increase in the amount of turn and unordered structure was observed on thermal denaturation. The results indicate that thermally denatured RNase A contains significant amounts of secondary structure (11% helix and 17% beta-sheet), consistent with previous results reported for circular dichroism, and with a relatively compact structure, as revealed by dynamic light scattering. These results are in contrast to those of amide protection experiments reported recently [Robertson, A. D., & Baldwin, R. L. (1991) Biochemistry 30, 9907-9914] which indicated no stable hydrogen-bonded structure under these experimental conditions. Possible explanations for this apparent discrepancy are given.

引用

页码：1351 / 1355

页数：5