PMID- 34638544
OWN - NLM
STAT- MEDLINE
DCOM- 20211027
LR  - 20211027
IS  - 1422-0067 (Electronic)
IS  - 1422-0067 (Linking)
VI  - 22
IP  - 19
DP  - 2021 Sep 22
TI  - Tyrp1 Mutant Variants Associated with OCA3: Computational Characterization of 
      Protein Stability and Ligand Binding.
LID - 10.3390/ijms221910203 [doi]
LID - 10203
AB  - Oculocutaneous albinism type 3 (OCA3) is an autosomal recessive disorder caused 
      by mutations in the TYRP1 gene. Tyrosinase-related protein 1 (Tyrp1) is involved 
      in eumelanin synthesis, catalyzing the oxidation of 
      5,6-dihydroxyindole-2-carboxylic acid oxidase (DHICA) to 
      5,6-indolequinone-2-carboxylic acid (IQCA). Here, for the first time, four 
      OCA3-causing mutations of Tyrp1, C30R, H215Y, D308N, and R326H, were investigated 
      computationally to understand Tyrp1 protein stability and catalytic activity. 
      Using the Tyrp1 crystal structure (PDB:5M8L), global mutagenesis was conducted to 
      evaluate mutant protein stability. Consistent with the foldability parameter, 
      C30R and H215Y should exhibit greater instability, and two other mutants, D308N 
      and R326H, are expected to keep a native conformation. SDS-PAGE and Western blot 
      analysis of the purified recombinant proteins confirmed that the foldability 
      parameter correctly predicted the effect of mutations critical for protein 
      stability. Further, the mutant variant structures were built and simulated for 
      100 ns to generate free energy landscapes and perform docking experiments. Free 
      energy landscapes formed by Y362, N378, and T391 indicate that the binding clefts 
      of C30R and H215Y mutants are larger than the wild-type Tyrp1. In docking 
      simulations, the hydrogen bond and salt bridge interactions that stabilize DHICA 
      in the active site remain similar among Tyrp1, D308N, and R326H. However, the 
      strengths of these interactions and stability of the docked ligand may decrease 
      proportionally to mutation severity due to the larger and less well-defined 
      natures of the binding clefts in mutants. Mutational perturbations in mutants 
      that are not unfolded may result in allosteric alterations to the active site, 
      reducing the stability of protein-ligand interactions.
FAU - Patel, Milan H
AU  - Patel MH
AUID- ORCID: 0000-0002-0938-2805
AD  - National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
FAU - Dolinska, Monika B
AU  - Dolinska MB
AD  - National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
FAU - Sergeev, Yuri V
AU  - Sergeev YV
AUID- ORCID: 0000-0002-7204-6572
AD  - National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA.
LA  - eng
GR  - ZIA EY000476-10/EY/NEI NIH HHS/United States
PT  - Journal Article
DEP - 20210922
PL  - Switzerland
TA  - Int J Mol Sci
JT  - International journal of molecular sciences
JID - 101092791
RN  - 0 (Ligands)
RN  - 0 (Melanins)
RN  - 0 (Membrane Glycoproteins)
RN  - 0 (Quinoxalines)
RN  - 12627-86-0 (eumelanin)
RN  - A16F9MIN3Z (imidazo(1,2-a)quinoxaline-2-carboxylic acid)
RN  - EC 1.- (Oxidoreductases)
RN  - EC 1.14.18.- (TYRP1 protein, human)
RN  - EC 1.14.18.- (tyrosinase-related protein-1)
RN  - Rufous oculocutaneous albinism
SB  - IM
MH  - Albinism, Oculocutaneous/*genetics
MH  - Computational Biology
MH  - Humans
MH  - Ligands
MH  - Melanins/*biosynthesis
MH  - Melanocytes/*metabolism
MH  - Membrane Glycoproteins/*genetics
MH  - Molecular Docking Simulation
MH  - Oxidoreductases/*genetics/metabolism
MH  - Protein Folding
MH  - Protein Stability
MH  - Quinoxalines/metabolism
PMC - PMC8508144
OTO - NOTNLM
OT  - OCA3
OT  - Tyrp1
OT  - disease-related mutant variants
OT  - melanogenesis
OT  - molecular modeling
COIS- The authors declare no conflict of interest. The funders had no role in the 
      design of the study; in the collection, analyses, or interpretation of data; in 
      the writing of the manuscript; or in the decision to publish the results.
EDAT- 2021/10/14 06:00
MHDA- 2021/10/28 06:00
PMCR- 2021/09/22
CRDT- 2021/10/13 01:02
PHST- 2021/08/16 00:00 [received]
PHST- 2021/09/16 00:00 [revised]
PHST- 2021/09/17 00:00 [accepted]
PHST- 2021/10/13 01:02 [entrez]
PHST- 2021/10/14 06:00 [pubmed]
PHST- 2021/10/28 06:00 [medline]
PHST- 2021/09/22 00:00 [pmc-release]
AID - ijms221910203 [pii]
AID - ijms-22-10203 [pii]
AID - 10.3390/ijms221910203 [doi]
PST - epublish
SO  - Int J Mol Sci. 2021 Sep 22;22(19):10203. doi: 10.3390/ijms221910203.