Bokstedt periodicity generator via K-theory

For a prime field $k$ of characteristic $p > 2$, we construct the B\"okstedt periodicity generator $v \in THH_2(k)$ as an explicit class in the stabilization of $K$-theory with coefficients $K(k,-)$, and we show directly that $v$ is not nilpotent in $THH(k)$. This gives an alternative proof of the "multiplicative" part of B\"okstedt periodicity.