Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.

The hydrogen-exchange behavior of the low-pH molten globule of human alpha-lactalbumin, containing all four disulfides, has been examined and compared with that of a single disulfide variant, [28-111] alpha-lactalbumin, and of a series of proline variants of [28-111] alpha-lactalbumin. The small dif...

Ամբողջական նկարագրություն

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Հիմնական հեղինակներ: Last, A, Schulman, B, Robinson, C, Redfield, C
Ձևաչափ: Journal article
Լեզու:English
Հրապարակվել է: 2001
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author Last, A
Schulman, B
Robinson, C
Redfield, C
author_facet Last, A
Schulman, B
Robinson, C
Redfield, C
author_sort Last, A
collection OXFORD
description The hydrogen-exchange behavior of the low-pH molten globule of human alpha-lactalbumin, containing all four disulfides, has been examined and compared with that of a single disulfide variant, [28-111] alpha-lactalbumin, and of a series of proline variants of [28-111] alpha-lactalbumin. The small differences in hydrogen-exchange protection exhibited by these partially folded species were compared by mixing two or more proteins and monitoring their exchange simultaneously using mass spectrometry. The effect of single proline mutations within each alpha-domain helix on hydrogen-exchange protection has been investigated using six proline variants of [28-111] alpha-lactalbumin, L11P, L12P, M30P, I95P, K108P and Q117P. The results show that proline mutations in the A, B, C and D alpha-helices lead to a loss of hydrogen-exchange protection for residues in the local helix without perturbing hydrogen-exchange protection in other regions of the protein. Thus, local unfolding of the A, B, C and D helices does not significantly alter the packing and solvent accessibility of other regions of the molten globule. By contrast, introduction of a proline residue in the C-terminal 3(10) helix produces a larger and more widespread loss of hydrogen-exchange protection, demonstrating that longer-range perturbations of the molten globule have occurred. Thus, residues in this C-terminal region must be involved in contacts that are critical for the stabilisation of the compact molten globule structure.
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spelling oxford-uuid:306674e9-6acf-4abf-866e-7f8198e4b3aa2022-03-26T13:01:12ZProbing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.Journal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:306674e9-6acf-4abf-866e-7f8198e4b3aaEnglishSymplectic Elements at Oxford2001Last, ASchulman, BRobinson, CRedfield, CThe hydrogen-exchange behavior of the low-pH molten globule of human alpha-lactalbumin, containing all four disulfides, has been examined and compared with that of a single disulfide variant, [28-111] alpha-lactalbumin, and of a series of proline variants of [28-111] alpha-lactalbumin. The small differences in hydrogen-exchange protection exhibited by these partially folded species were compared by mixing two or more proteins and monitoring their exchange simultaneously using mass spectrometry. The effect of single proline mutations within each alpha-domain helix on hydrogen-exchange protection has been investigated using six proline variants of [28-111] alpha-lactalbumin, L11P, L12P, M30P, I95P, K108P and Q117P. The results show that proline mutations in the A, B, C and D alpha-helices lead to a loss of hydrogen-exchange protection for residues in the local helix without perturbing hydrogen-exchange protection in other regions of the protein. Thus, local unfolding of the A, B, C and D helices does not significantly alter the packing and solvent accessibility of other regions of the molten globule. By contrast, introduction of a proline residue in the C-terminal 3(10) helix produces a larger and more widespread loss of hydrogen-exchange protection, demonstrating that longer-range perturbations of the molten globule have occurred. Thus, residues in this C-terminal region must be involved in contacts that are critical for the stabilisation of the compact molten globule structure.
spellingShingle Last, A
Schulman, B
Robinson, C
Redfield, C
Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.
title Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.
title_full Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.
title_fullStr Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.
title_full_unstemmed Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.
title_short Probing subtle differences in the hydrogen exchange behavior of variants of the human alpha-lactalbumin molten globule using mass spectrometry.
title_sort probing subtle differences in the hydrogen exchange behavior of variants of the human alpha lactalbumin molten globule using mass spectrometry
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