Study of effects of pH on the stability of domains in myosin rod by high-resolution differential scanning calorimetry.


Differential scanning calorimetry (DSC) has detected at least six quasi-independent structure domains in myosin rod [Potekhin, S.A., & Privalov, P.L. (1978) Biofizika 23, 219-223]. These domains were found to be remarkably sensitive to pH in the physiological range, i.e., pH 6-8. We compared the thermodynamic characteristics, and studied effects of pH on the stability, of individual domains in rod, light meromyosin (LMM), and subfragment 2 (S-2). In rod, the lowest stability domain (approximately 400 amino acid residues per double strand), with a Tm of 42.4 degrees C, a delta Hcal of 190 kcal/mol, and a delta G of 3.39 kcal/mol, at pH 7.02, destabilized by absorption of protons, is located at the LMM/S-2 junction and split into two parts, one associated with S-2 (approximately 100 residues per double strand) and the other with LMM (300 residues per double strand). The fragment with S-2 is likely a part of the "hinge" suggested by Swenson and Ritchie [(1980) Biochemistry 19, 5371-5375]. All other domains of rod released protons on melting. The domains located in S-2 were the most sensitive to pH and released a total of 0.9 proton on melting. The thermal meltings of all domains in myosin rod, LMM, and S-2 were independent of each other, and enthalpies of melting were additive in the whole pH range studied. Their sensitivities to pH and KCl were also unaffected by the presence or absence of other fragments. For example, domains in an isolated S-2 behaved similarly as they were in the rod, and so were domains in LMM.(ABSTRACT TRUNCATED AT 250 WORDS) Study holds ProTherm entries: 4095, 4096, 4097, 4098, 4099, 4100, 4101, 4102, 4103, 4104, 4105, 4106, 4107, 4108, 4109, 4110, 4111, 4112, 4113, 4114, 4115, 4116, 4117, 4118, 4119, 4120, 4121, 4122, 4123, 4124, 4125, 4126, 4127, 4128, 4129, 4130, 4131, 4132, 4133, 4134, 4135, 4136, 4137, 4138, 4139, 4140, 4141, 4142, 4143, 4144, 4145, 4146, 4147, 4148, 4149, 4150, 4151, 4152, 4153, 4154, 4155, 4156, 4157, 4158, 4159, 4160, 4161, 4162, 4163, 4164, 4165, 4166, 4167, 4168, 4169, 4170, 4171, 4172, 4173, 4174, 4175, 4176, 4177, 4178, 4179, 4180 Extra Details: additive : EDTA(1 mM), quasi-independent structure domains; hinge; fragments;,protonation; histidine residue

Submission Details

ID: SKvZ5gGx

Submitter: Connie Wang

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

Version: 1

Publication Details
Bertazzon A;Tsong TY,Biochemistry (1990) Study of effects of pH on the stability of domains in myosin rod by high-resolution differential scanning calorimetry. PMID:2207086
Additional Information

Study Summary

Number of data points 213
Proteins Calmodulin ; Myosin light chain kinase 2, skeletal/cardiac muscle
Unique complexes 1
Assays/Quantities/Protocols Experimental Assay: dCp pH:7.02 ; Experimental Assay: dCp pH:6.79 ; Experimental Assay: dHcal pH:6.79 ; Experimental Assay: Tm pH:6.79 ; Experimental Assay: dCp pH:6.45 ; Experimental Assay: dCp pH:7.03 ; Experimental Assay: dHcal pH:7.03 ; Experimental Assay: Tm pH:7.03 ; Experimental Assay: dCp pH:6.75 ; Experimental Assay: dHcal pH:6.75 ; Experimental Assay: Tm pH:6.75 ; Experimental Assay: dCp pH:6.4 ; Experimental Assay: dHcal pH:6.4 ; Experimental Assay: Tm pH:6.4 ; Experimental Assay: dCp pH:6.23 ; Experimental Assay: dHcal pH:6.23 ; Experimental Assay: Tm pH:6.23 ; Experimental Assay: dHcal pH:7.31 ; Experimental Assay: Tm pH:7.31 ; Experimental Assay: dHvH pH:7.31 ; Experimental Assay: dHcal pH:7.02 ; Experimental Assay: Tm pH:7.02 ; Experimental Assay: dHvH pH:7.02 ; Experimental Assay: dHcal pH:6.95 ; Experimental Assay: Tm pH:6.95 ; Experimental Assay: dHvH pH:6.95 ; Experimental Assay: dHcal pH:6.85 ; Experimental Assay: Tm pH:6.85 ; Experimental Assay: dHvH pH:6.85 ; Experimental Assay: dHcal pH:6.65 ; Experimental Assay: Tm pH:6.65 ; Experimental Assay: dHvH pH:6.65 ; Experimental Assay: dHcal pH:6.45 ; Experimental Assay: Tm pH:6.45 ; Experimental Assay: dHvH pH:6.45 ; Experimental Assay: dHcal pH:6.35 ; Experimental Assay: Tm pH:6.35 ; Experimental Assay: dHvH pH:6.35 ; Experimental Assay: dHcal pH:6.15 ; Experimental Assay: Tm pH:6.15 ; Experimental Assay: dHvH pH:6.15 ; Experimental Assay: dHcal pH:6.03 ; Experimental Assay: Tm pH:6.03 ; Experimental Assay: dHvH pH:6.03

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 PDB Entries

Structure ID Release Date Resolution Structure Title
4QNH 2014-06-17T00:00:00+0000 2.02 Calcium-calmodulin (T79D) complexed with the calmodulin binding domain from a small conductance potassium channel SK2-a
6ALE 2017-08-07T00:00:00+0000 2.5 A V-to-F substitution in SK2 channels causes Ca2+ hypersensitivity and improves locomotion in a C. elegans ALS model
1OOJ 2003-03-03T00:00:00+0000 2.11 Structural genomics of Caenorhabditis elegans : Calmodulin
2LV6 2012-06-29T00:00:00+0000 0 The complex between Ca-Calmodulin and skeletal muscle myosin light chain kinase from combination of NMR and aqueous and contrast-matched SAXS data
2MES 2013-09-26T00:00:00+0000 0 Backbone 1H, 13C, 15N resonance assignments of calcium-bound calmodulin in complex with PSD95 N-terminal peptide
2RRT 2011-04-27T00:00:00+0000 0 Solution structure of Magnesium-bound form of calmodulin C-domain E104D/E140D mutant
3KF9 2009-10-27T00:00:00+0000 2.6 Crystal structure of the SdCen/skMLCK complex
5H7D 2016-11-17T00:00:00+0000 2.57 Crystal structure of the YgjG-protein A-Zpa963-calmodulin complex

Relevant UniProtKB Entries

Percent Identity Matching Chains Protein Accession Entry Name
100.0 B Calmodulin P20689 MYLK2_RAT
100.0 B Calmodulin P07313 MYLK2_RABIT
100.0 B Calmodulin Q8VCR8 MYLK2_MOUSE
100.0 B Calmodulin Q9H1R3 MYLK2_HUMAN
100.0 B Calmodulin A4IFM7 MYLK2_BOVIN
93.5 A Calmodulin P18061 CALM_TRYCR
93.5 A Calmodulin P69098 CALM_TRYBG
93.5 A Calmodulin P69097 CALM_TRYBB
100.0 A Calmodulin P62184 CALM_RENRE
100.0 A Calmodulin P11121 CALM_PYUSP
100.0 A Calmodulin P02595 CALM_PATSP
92.3 A Calmodulin P53440 CALMF_NAEGR
94.2 A Calmodulin P11118 CALM_EUGGR
100.0 A Calmodulin P02594 CALM_ELEEL
91.4 A Calmodulin P05932 CALMB_ARBPU
96.5 A Calmodulin Q9HFY6 CALM_BLAEM
100.0 A Calmodulin Q40302 CALM_MACPY
91.9 A Calmodulin P62150 CALM_ORYLA
95.7 A Calmodulin O02367 CALM_CIOIN
91.2 A Calmodulin P27166 CALM_STYLE
91.2 A Calmodulin O97341 CALM_SUBDO
91.2 A Calmodulin A8I1Q0 CALM_HETTR
92.6 A Calmodulin P02598 CALM_TETPY
92.6 A Calmodulin A3E4D8 CALM_PROMN
92.6 A Calmodulin A3E3H0 CALM_PFIPI
92.6 A Calmodulin A3E4F9 CALM_KARVE
92.6 A Calmodulin A4UHC0 CALM_ALEFU
92.6 A Calmodulin O96081 CALMB_HALRO
92.6 A Calmodulin P62146 CALMA_ARBPU
98.3 A Calmodulin Q95NR9 CALM_METSE
97.4 A Calmodulin Q7T3T2 CALM_EPIAK
98.3 A Calmodulin P0DP35 CAM2B_XENLA
98.3 A Calmodulin P0DP34 CAM2A_XENLA
98.3 A Calmodulin P62151 CALM_TETCF
98.3 A Calmodulin P21251 CALM_STIJA
98.3 A Calmodulin Q6YNX6 CALM_SHEEP
98.3 A Calmodulin P62160 CALM_RABIT
98.3 A Calmodulin Q5RAD2 CALM_PONAB
98.3 A Calmodulin Q71UH6 CALM_PERFV
98.3 A Calmodulin P62156 CALM_ONCSP
98.3 A Calmodulin Q6PI52 CALM_DANRE
98.3 A Calmodulin Q6IT78 CALM_CTEID
98.3 A Calmodulin P62149 CALM_CHICK
98.3 A Calmodulin P62157 CALM_BOVIN
98.3 A Calmodulin P62144 CALM_ANAPL
98.3 A Calmodulin P0DP31 CALM3_RAT
98.3 A Calmodulin P0DP28 CALM3_MOUSE
98.3 A Calmodulin P0DP25 CALM3_HUMAN
98.3 A Calmodulin P0DP30 CALM2_RAT
98.3 A Calmodulin P0DP27 CALM2_MOUSE
98.3 A Calmodulin P0DP24 CALM2_HUMAN
99.1 A Calmodulin Q9UB37 CALM2_BRALA
98.3 A Calmodulin P0DP33 CALM1_XENLA
98.3 A Calmodulin P0DP29 CALM1_RAT
98.3 A Calmodulin P0DP26 CALM1_MOUSE
98.3 A Calmodulin P0DP23 CALM1_HUMAN
98.0 A Calmodulin Q8STF0 CALM_STRIE
99.3 A Calmodulin P62154 CALM_LOCMI
99.3 A Calmodulin P62152 CALM_DROME
99.3 A Calmodulin P62145 CALM_APLCA
99.3 A Calmodulin P62153 CALMA_HALRO
99.3 A Calmodulin P62148 CALM1_BRALA
99.3 A Calmodulin P62147 CALM1_BRAFL
98.6 A Calmodulin O16305 CALM_CAEEL