丙氨酸残基组成的310螺旋的微观结构侧视图：紫色为残基之间形成的氢键，其氢氧原子之间的距离为1.83 Å（183 pm）。The protein chain runs upwards, i.e., its N-terminus is at the bottom and its C-terminus at the top of the figure. Note that the sidechains point slightly downwards, i.e., towards the N-terminus.
Pauling L, Corey RB and Branson HR. (1951) "The Structure of Proteins: Two Hydrogen-Bonded Helical Configurations of the Polypeptide Chain", Proc. Nat. Acad. Sci. Wash., 37, 205.
