Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Formation of the Platelet Plug

Formation of the Platelet Plug

The platelet phase, the second stage of hemostasis, commences around 15-20 seconds after an injury. It follows and overlaps with the vascular phase, during which blood vessels constrict to minimize blood loss.
As the injured blood vessel contracts, endothelial cells undergo contraction, revealing collagen fibers in the basement membrane and underlying connective tissue. Furthermore, the plasma membrane of endothelial cells becomes adhesive, preparing the site for platelet adhesion. Platelets...

Structure and Function of Platelets

Structure and Function of Platelets

The cell fragments known as platelets are disc-shaped, with an average diameter of about 3 μm and a thickness of roughly 1 μm. They play a crucial role in the body's vascular clotting system, which also involves plasma proteins, blood cells, and blood vessel tissues.
Platelets are continually replenished, circulating in the bloodstream for 9-12 days before being removed by phagocytes, primarily in the spleen. A microliter of circulating blood contains between 150,000 and 450,000 platelets, with...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Do People Get the Friends They Want? A Cross-Cultural Investigation.

International journal of psychology : Journal international de psychologie·2026

Same author

Effects of the wavelength and irradiance level of short-wave blue light on mycelial growth and deoxynivalenol production in Gibberella zeae.

Fungal biology·2025

Same author

Second-generation lysocins as therapeutics for treating <i>Pseudomonas aeruginosa</i> infections.

Antimicrobial agents and chemotherapy·2025

Same author

<b>Functional characteristics of membrane vesicles produced by</b> <i><b>Streptococcus mitis</b></i>.

Journal of oral microbiology·2025

Same author

Nationwide surveillance of antibacterial susceptibility in bacterial respiratory pathogens in Japan, 2022-2023.

Journal of infection and chemotherapy : official journal of the Japan Society of Chemotherapy·2025

Same author

Effect of Sulfonamide Group Modification on Celecoxib: Molecular Features of Matrix Metalloproteinase Interactive UTX-121 Derivative.

Anticancer research·2025

Search research articles

Related Experiment Video

Updated: May 26, 2026

A Uniform Shear Assay for Human Platelet and Cell Surface Receptors via Cone-plate Viscometry

A Uniform Shear Assay for Human Platelet and Cell Surface Receptors via Cone-plate Viscometry

Published on: June 5, 2019

Characterization of recombinant Streptococcus mitis-derived human platelet aggregation factor.

Hisashi Ohkuni¹, Hideaki Nagamune, Nana Ozaki

¹Health Science Research Institute East Japan Co. Ltd, Kounosu, Saitama, Japan. h-okuni@nms.ac.jp

APMIS : Acta Pathologica, Microbiologica, Et Immunologica Scandinavica

|December 14, 2011

Summary

Recombinant Streptococcus mitis-derived human platelet aggregation factor (rSm-hPAF) exhibits potent hemolytic and platelet aggregation activities. This protein, similar to other cholesterol-dependent cytolysins, offers insights into bacterial virulence factors.

More Related Videos

Microfluidics in Assessing Platelet Function

Microfluidics in Assessing Platelet Function

Published on: November 8, 2024

Procoagulant Platelet Characterization by Measuring Phosphatidylserine Exposure and Microvesicle Release from Human Purified Platelets

Procoagulant Platelet Characterization by Measuring Phosphatidylserine Exposure and Microvesicle Release from Human Purified Platelets

Published on: November 29, 2024

Related Experiment Videos

Last Updated: May 26, 2026

A Uniform Shear Assay for Human Platelet and Cell Surface Receptors via Cone-plate Viscometry

A Uniform Shear Assay for Human Platelet and Cell Surface Receptors via Cone-plate Viscometry

Published on: June 5, 2019

Microfluidics in Assessing Platelet Function

Microfluidics in Assessing Platelet Function

Published on: November 8, 2024

Procoagulant Platelet Characterization by Measuring Phosphatidylserine Exposure and Microvesicle Release from Human Purified Platelets

Procoagulant Platelet Characterization by Measuring Phosphatidylserine Exposure and Microvesicle Release from Human Purified Platelets

Published on: November 29, 2024

Area of Science:

Microbiology
Immunology
Biochemistry

Background:

Streptococcus mitis-derived human platelet aggregation factor (Sm-hPAF) was previously purified.
Sm-hPAF was isolated from S. mitis strain Nm-65, found on the tooth surface of a Kawasaki disease patient.

Purpose of the Study:

To produce recombinant Sm-hPAF (rSm-hPAF) in Escherichia coli.
To determine if rSm-hPAF retains its platelet aggregation activity.

Main Methods:

Recombinant protein production in E. coli.
Hemolytic activity assays on mammalian erythrocytes.
Platelet aggregation assays.
Morphological confirmation using light and electron microscopy.

Main Results:

Recombinant Sm-hPAF (rSm-hPAF) demonstrated potent hemolytic activity against human erythrocytes.
rSm-hPAF exhibited significant human platelet aggregation activity.
The amino-terminal domain of rSm-hPAF shares homology with pneumococcal fucolectin-related protein.
Other cholesterol-dependent cytolysins, suilysin (SLY) and pneumolysin (PLY), also showed human platelet aggregation activity.

Conclusions:

Recombinant Sm-hPAF conserves its platelet aggregation and hemolytic activities.
rSm-hPAF shares characteristics with cholesterol-dependent cytolysins, suggesting a role in bacterial pathogenesis.
The platelet aggregation activity of Sm-hPAF, SLY, and PLY provides new avenues for research into bacterial-host interactions.