I am using the \twocolumn tag to use the two-column layout in LaTeX. The problem is that this does not work properly and the text seems not to be fixed between the borders. Not sure if that minimal example helps, but at least you can see my includes and the text with which it happens.
\documentclass[12pt,a4paper, abstracton]{article}
\usepackage[utf8]{inputenc}
\usepackage[english]{babel}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage[backend=biber, sorting=none]{biblatex}
\usepackage{hyperref}
\usepackage[hyphenbreaks]{breakurl}
\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}
\begin{document}
\twocolumn
\section{Introduction}
Glutamate carboxypeptidase II (GCPII), N-acetyl-L-aspartyl-L-glutamate peptidase I (NAALADase I), NAAG peptidase or prostate-specific membrane antigen (PSMA) \dots
\end{document}
Screenshot of left column in PDF that shows the problem
Why does LaTeX write from the first column into the second column and how can I fix that? I would like to avoid change each line separately, where that happens. I am looking for a global solution.
Since the workarounds of the accepted answer were not satisfactory to me, I kept searching and found a more adequate and fast workaround, adding to my preamble the following:
\setlength{\emergencystretch}{3em}
The length 3em can be changed as needed, just keep it as low as possible in order to preserve optimal appearance.
More details here.