Parvovirus B19 capsid protein VP1 (VP1) (VP1)

Parvovirus B19 capsid protein VP1 is a minor structural component of the human parvovirus B19 (B19V) capsid, constituting approximately 5% of the 60-subunit icosahedral shell [6]. It is distinguished from the major capsid protein VP2 by an N-terminal extension called the VP1 unique region (VP1u), which plays a pivotal role in viral pathogenesis and host cell entry [1]. This VP1u region contains a receptor-binding domain (RBD) that mediates the virus's high tropism for erythroid progenitor cells and a phospholipase A2 (PLA2) motif required for endosomal escape [1, 9]. Because it contains the primary neutralizing epitopes of the virus, VP1 is a major target for the host immune system and therapeutic interventions like intravenous immunoglobulin (IVIG) [16, 19]. Clinically, B19V infection is associated with erythema infectiosum, transient aplastic crisis, and hydrops fetalis, with VP1-mediated inflammatory signaling also linked to arthropathy and cardiomyopathy [7, 12, 15]. Current therapeutic research focuses on developing VP1-based vaccines and small-molecule inhibitors of its PLA2 activity to prevent viral replication [3, 14]. The protein's enzymatic activity is calcium-dependent and can be inhibited in vitro by compounds such as manoalide [3, 5]. VP1u also serves as a potential biomarker for erythroid cell targeting due to its specific interaction with progenitor cells [1]. Safety concerns in targeting VP1 include potential cross-reactivity with host proteins and the risk of inflammatory side effects observed in early vaccine trials [11, 14]. Overall, VP1 is a critical multifunctional protein that serves as both a structural element and a key driver of viral infectivity and disease [1, 6].

Other names

Minor capsid protein VP1B19V VP1VP1 unique regionVP1u

Neutralization of viral particles and inhibition of phospholipase A2 activity.