Protractor is an end-to-end test framework for AngularJS. The official version is built on Node.js and Selenium WebDriverJS.
There is currently no way to integrate Protractor tests into Test Explorer (that I know of).
Thankfully there is Protractor.NET, a .NET port of Protractor built on top of Selenium WebDriver for .NET. It allows us to write Angular UI tests using .NET testing frameworks such as NUnit, and arguably produces more readable tests because there’s no need to use promises.