Introduction: The Delta (B.1.617.2) variant encodes an S protein with ten mutations (T19R, G142D, del 156, del 157, R158G, L452R, T478K, D614G, P681R, and D950N), two of which are in the RBD (L452R and T478K).
The Development of SARS-CoV-2 Variants: The Gene Makes the Disease.
PMID: 34940505
2021
Journal of developmental biology
Introduction: Different mutations have been observed in this residue, such as the P681H mutation in the Alpha variant, P681R in Delta and DeltaP681 in the Indian lineage B.1.617 (Table 2).
Introduction: It has been proposed that viruses bearing P681R fuse with the plasma membranes of uninfected cells, a critical step in disease, almost three times faster than control ones.
Introduction: It has recently been documented that P681R provides a pre-active state that could facilitate virus-cell binding and, in general, cell infection.
Introduction: It remains unclear whether the presence of T478K or P681R could be decisive, causing this variant's increased strength.
Introduction: Nevertheless, researchers suggest that the
Semi-Supervised Pipeline for Autonomous Annotation of SARS-CoV-2 Genomes.
Result: This includes observations of deletions early in the S protein and differentiation between substitutions P681H, which is a mutation of interest, and P681R.
SARS-CoV-2 Delta Variant Displays Moderate Resistance to Neutralizing Antibodies and Spike Protein Properties of Higher Soluble ACE2 Sensitivity, Enhanced Cleavage and Fusogenic Activity.
Result: A prior study showed that convalescent sera and vaccine-elicited antibody neutralization titers against pseudoviruses bearing spikes containing L452R-E484Q-P681R substitutions displayed 2-5-fold reduction, compared to the neutralization titers against WT(D614G) pseudoviruses.
Result: B.1.429 pseudoviruses that lack P681R or P681H substitutions near the furin cleavage site displayed inefficient spike cleavage, whereas the furin cleavage site ( PRRA)-deleted spike lacked cleavage.
Result: For all pseudoviruses bearing the P681R spike substitution, including B.1.617.1, B.1.617.2, Wuhan-Hu-1 +
Role of Q675H Mutation in Improving SARS-CoV-2 Spike Interaction with the Furin Binding Pocket.
Discussion: Furthermore, B.1.617 lineage carries the P681R mutation in the furin cleavage site, which increases S1/S2 cleavability, thus enhancing the viral fusion to the host cell membrane.
SARS-CoV-2 Variants: Mutations and Effective Changes.
PMID: 34975266
2021
Biotechnology and bioprocess engineering
Abstract: Certain mutations (D614G, E484K, N501Y, K417N, L452R and P681R) have appeared across several different strains, often accompanied by others that may be complementary working together to confer increased infectivity, fitness, or resistance to neutralization.
Analysis of Clinical Characteristics and Virus Strains Variation of Patients Infected With SARS-CoV-2 in Jiangsu Province-A Retrospective Study.
Result: In addition to the above mutations, amino acid substitutions of p.
Discussion: In addition, 20% of SNP changes occurred in the S gene, such as p.Asp501Tyr, p.Pro681His, and p.Pro681Arg.
Discussion: The p.Pro681Arg mutation causes a small increase in proteolytic processing that might have an effect on viral replication, transmissibility, or pathogenic properties.
Discussion: The p.Pro681Arg mutation, was first identified in Uganda in September 2020, is designated a variant of interest in Africa and with subsequent spread to other countries.
Differences in Clinical Characteristics Between Delta Variant and Wild-Type SARS-CoV-2 Infected Patients.
Discussion: Compared to other SARS-CoV-2 strains, the delta variant possesses notable mutations L452R, T478K, and E484Q in the RBD of S protein and P681R in the S1/S2 site.
Discussion: Moreover, within S1/S2 site P681R mutation enabled S protein to be less acidic and made furin in the host much easier to cleave, adding viral infectivity and transmissibility.
Tracking SARS-CoV-2 Spike Protein Mutations in the United States (January 2020-March 2021) Using a Statistical Learning Strategy.
Conclusion: However, we note that our analyses also identified a haplotype N6 (Table 2) that exhibits the subsequently well-documented mutation P681R, characteristic of the Delta variant that has dominated infections world-wide during the latter half of 2021.
Genome Sequencing Reveals a Mixed Picture of SARS-CoV-2 Variant of Concern Circulation in Eastern Uttar Pradesh, India.
Abstract: Signature substitution at positions S:L452R, S:P681R, and S:D614G were commonly detected in the Delta, Delta AY.1, and Kappa variants whereas S:T19R and S:T478K were confined to Delta and Delta AY.1 variants only.
Result: Signature substitutions at positions L452R and P681R were commonly detected in the Delta, Delta AY.1, and Kappa variant whereas T19R, T478K, and D614G were confined to Delta and Delta AY.1 variant only.
ViMRT
SARS_CoV_2 mutation literature information.
PMID: 
2021
Frontiers in immunology
