Virus Entry: Receptor Binding & Membrane Fusion

🦠 Virus Entry Mechanism

Step: Approaching host cell

Spike–receptor compatibility: 0.50

Entry pathway

Endosomal pH trigger: 7.40

Binding status—

Entry pathway—

Genome release—

Simulated step—

Attempts (fail / bound)0 / 0

Receptor specificity = tropism
A spike protein only binds a molecularly complementary receptor — this lock-and-key match is why SARS-CoV-2 spike needs ACE2, HIV gp120 needs CD4 (+ a co-receptor), and influenza hemagglutinin needs sialic acid. Blocking that interface is a real antiviral strategy.

Virus approaching the host-cell membrane