A comparison of the energetics of annexin I and annexin V.


The annexins comprise a family of soluble Ca2+- and phospholipid-binding proteins. Although highly similar in three-dimensional structure, different annexins are likely to exhibit different biochemical and functional properties and to play different roles in various membrane related events. Since it must be expected that these functional differences arise from differences in the characteristic thermodynamic parameters of these proteins, we performed high-sensitivity differential scanning microcalorimetry (DSC) and isothermal guanidinium hydrochloride (GdnHCl)-induced unfolding studies on annexin I and compared its thermodynamic parameters with those of annexin V published previously. The DSC data were analyzed using a model that permits quantitative treatment of the irreversible reaction. It turned out, however, that provided a heating rate of 2 K min-1 is used, unfolding of annexin I can be described satisfactorily in terms of a simple two-state reaction. At pH 6.0 annexin I is characterized by the following thermodynamic parameters: t1/2=61.8 degrees C, DeltaHcal=824 kJ mol-1 and DeltaCp=19 kJ mol-1 K-1. These parameters result in a stability value of DeltaG0D (20 degrees C)=51 kJ mol-1. The GdnHCl induced isothermal unfolding of annexin I in Mes buffer (pH 6.0), yielded DeltaG0D (buffer) values of 48, 60 and 36 kJ mol-1 at 20, 12 and 5 degrees C, respectively. These DeltaG0D values are in reasonable agreement with the values obtained from the DSC studies. The comparison of annexin I and annexin V under identical conditions (pH 8.0 or pH 6.0) shows that despite the pronounced structural homology of these two members of the annexin familiy, the stability parameters are remarkably different. This difference in stability is consistent with and provides a thermodynamic basis for the potential different in vivo functions proposed for these two annexins. Study holds ProTherm entries: 6177, 6178, 6179, 6180, 6181, 6182, 6183, 6184, 6185, 6186, 6187, 6188, 6189 Extra Details: annexins; DSC; irreversible denaturation;,heat capacity; stability parameters

Submission Details

ID: i5bZhnyx3

Submitter: Connie Wang

Submission Date: April 24, 2018, 8:31 p.m.

Version: 1

Publication Details
Rosengarth A;Rösgen J;Hinz HJ;Gerke V,J. Mol. Biol. (1999) A comparison of the energetics of annexin I and annexin V. PMID:10329195
Additional Information

Study Summary

Number of data points 33
Proteins Annexin A1 ; Annexin A1
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: dG temp:5.0 C ; Experimental Assay: dG temp:12.0 C ; Experimental Assay: dG temp:20.0 C ; Experimental Assay: dHcal pH:3.2 ; Experimental Assay: Tm pH:3.2 ; Experimental Assay: dHvH pH:3.2 ; Experimental Assay: dHcal pH:3.4 ; Experimental Assay: Tm pH:3.4 ; Experimental Assay: dHvH pH:3.4 ; Experimental Assay: dHcal pH:3.6 ; Experimental Assay: Tm pH:3.6 ; Experimental Assay: dHvH pH:3.6 ; Experimental Assay: dHcal pH:3.8 ; Experimental Assay: Tm pH:3.8 ; Experimental Assay: dHvH pH:3.8 ; Experimental Assay: dHcal pH:4.0 ; Experimental Assay: Tm pH:4.0 ; Experimental Assay: dHvH pH:4.0 ; Experimental Assay: dHcal pH:4.5 ; Experimental Assay: Tm pH:4.5 ; Experimental Assay: dHvH pH:4.5 ; Experimental Assay: dHcal pH:5.0 ; Experimental Assay: Tm pH:5.0 ; Experimental Assay: dHvH pH:5.0 ; Experimental Assay: dHcal pH:6.0 ; Experimental Assay: Tm pH:6.0 ; Experimental Assay: dHvH pH:6.0 ; Experimental Assay: dHcal pH:7.0 ; Experimental Assay: Tm pH:7.0 ; Experimental Assay: dHvH pH:7.0 ; Experimental Assay: dHcal pH:8.0 ; Experimental Assay: Tm pH:8.0 ; Experimental Assay: dHvH pH:8.0

Structure view and single mutant data analysis

Study data

No weblogo for data of varying length.
Colors: D E R H K S T N Q A V I L M F Y W C G P

Data Distribution

Studies with similar sequences (approximate matches)

Correlation with other assays (exact sequence matches)

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 Annexin A1 P04083 ANXA1_HUMAN
99.7 Annexin A1 Q5REL2 ANXA1_PONAB
99.7 Annexin A1 A5A6M2 ANXA1_PANTR
91.0 Annexin A1 Q8HZM6 ANXA1_HORSE
90.4 Annexin A1 P14087 ANXA1_CAVCU