Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2011 Dec 20;50(50):10771-80.
doi: 10.1021/bi201476a. Epub 2011 Nov 22.

Osteogenesis imperfecta missense mutations in collagen: structural consequences of a glycine to alanine replacement at a highly charged site

Affiliations

Osteogenesis imperfecta missense mutations in collagen: structural consequences of a glycine to alanine replacement at a highly charged site

Jianxi Xiao et al. Biochemistry. .

Abstract

Glycine is required as every third residue in the collagen triple helix, and a missense mutation leading to the replacement of even one Gly in the repeating (Gly-Xaa-Yaa)(n) sequence with a larger residue leads to a pathological condition. Gly to Ala missense mutations are highly underrepresented in osteogenesis imperfecta (OI) and other collagen diseases, suggesting that the smallest replacement residue, Ala, might cause the least structural perturbation and mildest clinical consequences. The relatively small number of Gly to Ala mutation sites that do lead to OI must have some unusual features, such as greater structural disruption because of local sequence environment or location at a biologically important site. Here, peptides are used to model a severe OI case in which a Gly to Ala mutation is found within a highly stabilizing Lys-Gly-Asp sequence environment. Nuclear magnetic resonance, circular dichroism, and differential scanning calorimetry studies indicate this Gly to Ala replacement leads to a substantial loss of triple-helix stability and nonequivalence of the Ala residues in the three chains such that only one of the three Ala residues is capable of forming a good backbone hydrogen bond. Examination of reported OI Gly to Ala mutations suggests their preferential location at known collagen binding sites, and we propose that structural defects caused by Ala replacements may lead to pathology when they interfere with interactions.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Thermal transitions of peptide set T1-645 with a Gly to Ala mutation. (A) CD thermal transition of T1-645 (black) and T1-645[G16A] (gray) in 20mM PBS, pH 7.0; (B) CD thermal transition of T1-645 (black) and T1-645[G16A] (gray) in 0.1M acetic acid pH 2.9; (C) DSC profile of T1-645 (black) and T1-645[G16A] (gray) in 20mM PBS, pH 7.0; (D) DSC profile of T1-645 (black) and T1-645(G16A) (gray) in 0.1M acetic acid, pH 2.9.
Figure 2
Figure 2
HSQC spectra of peptides T1-645 (left) and T1-645[G16A] (right) at pH 7, in 2mM PBS and 15mM NaCl at 0°C. Peptide sequences are shown at the top with 15N labeled residues underlined. The peaks corresponding to the monomer and trimer states are denoted with a superscript M or T, respectively.
Figure 3
Figure 3
Thermal stability of the Gly to Ala mutation peptide T1-655 set. (A) CD thermal transition of T1-655 (black) and T1-655[G16A] (gray) in PBS pH 7.0; (B) CD thermal transition of T1-655 (black) and T1-655[G16A] (gray) in 0.1M acetic acid pH 2.9; (C) DSC profile of T1-655 (black) and T1-655[G16A] (gray) in PBS pH 7.0; and (D) DSC profile of of T1-655 (black) and T1-655[G16A] (gray) in 0.1M acetic acid pH 2.9.
Figure 4
Figure 4
NMR studies of peptide set T1-655. Peptide sequences are shown at the top with 15N labeled residues in red color. (A) Overlapped 1H-15N HSQC spectra of peptide T1-655 at pH 7 (blue) and pH 3 (red) at 20°C; (B) Overlapped1H-15N HSQC spectra of peptide T1-655[G16A] at pH 7 (blue) and pH 3 (red) at 0°C. The peaks corresponding to the monomer and trimer states are denoted with a superscript M or T, respectively. Minor monomer resonances arise due to cis-trans isomerization in the unfolded state of the Pro/Hyp-rich chains [34].
Figure 5
Figure 5
Amide proton NH temperature gradients of peptide set T1-655. (A) Amide proton NH temperature gradient (ppb/°C) of peptide T1-655 at pH 7 (black) and pH 3 (gray); (B) Amide proton NH temperature gradient (ppb/°C) of peptide T1-655[G16A] at pH 7 (black) and pH 3 (gray); The black dashed horizontal line corresponds to a value of -4.6 ppb/°C, a cut-off for hydrogen bonding, with less negative values indicative of hydrogen bonding.
Figure 6
Figure 6. Stability calculation plots with Gly to Ala mutation in COL1A1
The horizontal axis is triplet number from N-terminal to C-terminal (from 0 to 338). The Silence classification of OI clinical phenotype is color coded: Red for mild OI I; blue diamonds for mild/moderate OI IV; green hexagons for severe OI III and pink triangles for lethal OI II. The site of the mutation modeled in peptides is indicated by an arrow.

Similar articles

Cited by

References

    1. Bella J, Eaton M, Brodsky B, Berman HM. Crystal and molecular structure of a collagen-like peptide at 1.9 A resolution. Science. 1994;266:75–81. - PubMed
    1. Kielty CM, Grant ME. The collagen family: strucutre, assembly, and organization in the extracellular matrix. In: Royes PM, Steinmann BU, editors. Connective tissue and its heritable disorders, molecular, genetic and medical aspects Edited by. Wiley Liss; New York: 2002. pp. 159–222.
    1. Ramachandran GN. Structure of Collagen at the Molecular Level. In: Ramachandran GN, editor. Treatise on Collagen Edited by. Academic Press; New York: 1967. pp. 103–184.
    1. Rich A, Crick FH. The molecular structure of collagen. J Mol Biol. 1961;3:483–506. - PubMed
    1. Byers PH, Cole WG. Osteogenesis Imperfecta. In: Royce PM, Steinmann B, editors. Connective tissue and its hereditable disorders Edited by. Wiley-Liss; New York: 2002. pp. 385–430.

Publication types

MeSH terms