Wednesday, July 18 , 2018, 6:03 pm | Mostly Cloudy 71º

 
 
 
 

UCSB Reich Group Uses Lasers to Spatially, Temporally Control Release of Tagged Protein Inside Cell

Optogenetics, which uses light to control cellular events, is poised to become an important technology in molecular biology and beyond. The Reich Group in UC Santa Barbara’s Department of Chemistry and Biochemistry has made a major contribution to this emergent field by developing a light-activated nanocarrier that transports proteins into cells and releases them on command. The findings appear in the journal Molecular Pharmaceutics.

Reich
Norbert Reich and Demosthenes Morales. (Spencer Bruttig / UCSB photo)

Using inorganic gold nanoshells and a near-infrared laser, UCSB biochemistry professor Norbert Reich and graduate student Demosthenes Morales demonstrate for the first time a method that affords both spatial and temporal control over protein delivery in cells.

“You can point the laser at cells where and when you want a particular protein to be turned on,” Reich said. “And that means you can ask biological questions that you could never ask before because you’re able to say I want this one cell to do this.”

The researchers exploited the receptors on prostate cancer cells, which rely on the recognition of a C-end rule internalizing peptide that has been fused to the end of a green fluorescent protein. This peptide is very specific for the receptor and once the two meet, it actually takes in the protein-loaded nanoparticles and shepherds them into the cell via endocytosis, a process that brings large molecules into cells.

The team used a modular nickel linking layer on the surface of the nanoparticles that is able to support different kinds of proteins fused with a polyhistidine tag commonly found on proteins expressed in labs.

“We want this to be applicable to any type of protein that has a polyhistidine tail,” lead author Morales said, “so if you synthesize or grow proteins in a lab, you can easily load the protein onto our nanoparticles.”

While the Reich Group’s hollow gold nanoshells are effective carriers, transporting large biomolecules such as proteins into cells is only half the battle. In order for the protein to be effective once inside the cell, it must be released from the vesicle (endosome) holding it. The UCSB design enables that to happen.

When we excite these hollow gold nanoshells with light, the surface of the nanoparticle becomes somewhat hot,” Morales said. “The light not only releases the cargo that’s on the surface but also causes the formation of vapor bubbles, which expand and eventually pop the vesicle, allowing for endosome escape.”

The Reich Group’s construct is designed around the advantage of protein delivery’s specificity. “The best thing about our platform is that it has a wide range of applicability,” Morales noted. “Not only do we have the ability to target with a laser where and when we want to release our therapeutic, but we also leverage the fact that the protein itself is very specific. We have specificity in terms of time and we have specificity toward the target. This is why proteins are very fascinating as a potent therapeutic.”

According to Reich, this technology has important implications for basic research.

“Biologists are going to make use of this kind of technology but they aren’t going to develop it,” Reich said. “There are a few people on campus who could use this technology so we have a unique opportunity at UCSB to be the lead in interfacing between the developers and the users.”

— Julie Cohen represents the UCSB Office of Public Affairs and Communications.

Support Noozhawk Today

You are an important ally in our mission to deliver clear, objective, high-quality professional news reporting for Santa Barbara, Goleta and the rest of Santa Barbara County. Join the Hawks Club today to help keep Noozhawk soaring.

We offer four membership levels: $5 a month, $10 a month, $25 a month or $1 a week. Payments can be made through Stripe below, or click here for information on recurring credit-card payments and a mailing address for checks.

Thank you for your vital support.

Become a Noozhawk Supporter

First name
Last name
Enter your email
Select your membership level
×

Payment Information

You are purchasing:

Payment Method

Pay by Credit Card:

Mastercard, Visa, American Express, Discover
One click only, please!

Pay with Apple Pay or Google Pay:

Noozhawk partners with Stripe to provide secure invoicing and payments processing.

  • Ask
  • Vote
  • Investigate
  • Answer

Noozhawk Asks: What’s Your Question?

Welcome to Noozhawk Asks, a new feature in which you ask the questions, you help decide what Noozhawk investigates, and you work with us to find the answers.

Here’s how it works: You share your questions with us in the nearby box. In some cases, we may work with you to find the answers. In others, we may ask you to vote on your top choices to help us narrow the scope. And we’ll be regularly asking you for your feedback on a specific issue or topic.

We also expect to work together with the reader who asked the winning questions to find the answer together. Noozhawk’s objective is to come at questions from a place of curiosity and openness, and we believe a transparent collaboration is the key to achieve it.

The results of our investigation will be published here in this Noozhawk Asks section. Once or twice a month, we plan to do a review of what was asked and answered.

Thanks for asking!

Click Here to Get Started >

Reader Comments

Noozhawk is no longer accepting reader comments on our articles. Click here for the announcement. Readers are instead invited to submit letters to the editor by emailing them to [email protected]. Please provide your full name and community, as well as contact information for verification purposes only.

Daily Noozhawk

Subscribe to Noozhawk's A.M. Report, our free e-Bulletin sent out every day at 4:15 a.m. with Noozhawk's top stories, hand-picked by the editors.

Sign Up Now >